Two questions: 1) losing coolant, 2) chewed-up drivebelt

[jessman1128]

WARNING: Long-post alert!!!

'96 GASE 2.4L, 230k-235k, auto tranny

First problem/question:
My car has suddenly started losing coolant. I first noticed it about a week ago when the low coolant light came on as I was leaving work. It was dark outside, so I couldn't see the coolant tank well enough to actually see the level of coolant, but I assumed the light was correct so I got a bottle of coolant left over from last summer out of my trunk and added some until I figured there was enough to at least make the tank half-full. It was a complete guess, since I couldn't actually see the level of coolant. Banged on the sensor a few times, started the car, light was out, drove home.

A few days later the scenario repeated itself. This time the light came on as I was arriving at work. It was light out, so I popped the hood and checked the tank. As far as I could tell, the tank was indeed empty - or at least mostly empty. Due to the nature of the tank plastic, and how old this one is, it's rather difficult to see the coolant level from the outside of the tank, even when it's light outside. Anyway, I forgot about it until that night when I was leaving work, so it was again dark when I was adding coolant. Added all the coolant I had, but I know it wasn't enough to fill the tank.

This morning the light came on as I was leaving home. Drove to the store, bought some more coolant, filled it up to the full-cold line, drove to work. The level now is slightly below the full-cold line.

I've been smelling coolant in the car while driving periodically for the last week or two - it started about a day before the low coolant light first came on. Coolant is not leaking inside the car - as I believe it would if this was a heater core problem. Coolant is not leaking onto the ground as far as I can tell. Coolant is not leaking into the oil, as far as I could tell.

My assumption then is that the coolant is only leaking while driving, and it's leaking in such a way that it's not leaving any glaringly obvious traces of the leak under the hood. By glaringly obvious I mean something that I would immediately notice just looking around at the areas I can see from the hood opening.

Could this possibly be a faulty pressure cap? Or should I be looking in some other direction?

Some of you may recall that I previously had a leaky water pump seal that eventually developed into a gushing water pump seal, and resulted in me shelling out a fair penny to have the water pump replaced - at which time they also replaced the thermostat and timing chain. I don't think that's relevant to the problem at hand, but I don't really know so I figured I'd mention it.


Second problem/question:
When I got to work this morning I left the engine running and popped the hood to watch for a few minutes to see if I could see any coolant leaking anywhere. I didn't see anything helpful, but I noticed my drivebelt didn't look quite right. Turned the engine off and discovered that my drivebelt was severely chewed up. This afternoon I borrowed a friend's car and drove up to Sears to buy a wrench - luckily I remembered what size wrench I needed for the belt tensioner! I had a replacement belt in the back seat (why? because when I replaced my alternator a month or two ago I bought a belt thinking I would replace it then, but when I got the current belt off I thought it didn't look all that bad so I put it back on - there was some mild wearing on the inner edge of the belt, but no severe frays or anything) - so I replaced the belt in the parking lot at work just a little bit ago.

While replacing the belt, I noticed two things I wanted to ask about:
1) One of the ridges in the alternator pulley has a minor nick that I'm quite sure wasn't there recently when I put the alternator on. By "nick" I mean a tiny section of the ridge has been pushed into the groove - the section is about as wide as the thinnest part of a thick paperclip.
2) The belt tensioner had some rubber residue embedded on it. The section of residue was about 2 inches long, and was dispersed more towards the outer edge of the tensioner wheel than the inner edge. I scraped it all off with my fingernail before putting the new belt on. It didn't peal off easily; I had to scratch it off a little bit at a time.

The old belt has about a 12-inch section on the inner edge that is really chewed up. Two sections have frayed threads still hanging on - a good chunk in between is completely missing - about one ridge worth's in width. I found one single-thread 3-4 inch piece in the engine compartment nearby, plus a wider 4-5 inch piece nearby that was part of the missing ridge from the belt.

The old belt was one of those Goodyear Gatorback belts, in case that matters.

The new belt is on now and appears to be working fine. Should I worry about the nick in the alternator pulley, the rubber residue that was on the belt tensioner, or the fact that the old belt was so severely chewed up? If so, what do I need to look at that might have caused those things?

Finally - this falls under the probably-not-relevant-but-you-never-know category - I live in Michigan. This winter - especially the last 1-2 months - has been especially brutal on our already-problematic roads. Potholes are springing up all over the place; little ones, medium-size ones, HUGE ones. I try to avoid as many as I can, but as many as there are in places it's impossible to miss them all. I have no idea how far up in the air water/slush/gravel can fly when it's, say, in a big pothole that you drive over unexpectedly. I mention that because I don't know if it's possible that any of the drivebelt issues could have been caused by flying "debris", if you will, from one of these potholes.

[rixGAphx]

Cliff's Notes:
* Mysterious disappearing coolant on a 4-cyl, with AF odor in the passenger compartment and no evidence of puddle on the ground.

* Old serpentine belt was trash; is new one gonna suffer same fate because of possible defect in alternator pulley or tensioner idler pulley?
* * *
* The main method for AF odor to enter the cabin is thru a leaking heater core.
Yours is prolly the original plastic sidetank core, and the hose nipples prolly have hairline cracks allowing leakage when the system is hot and under pressure.
The small, hot leak evaporates almost immediately, but some of the liquid dribbles down the heater core and into the cabin whence you can smell it.
It then drips into the condensate drip pan (which is there to catch condensate from the AC evaporator on humid summer days) and drains out the rubber drip tube onto the pavement as you drive along.

Your pressure cap may also be leaking, but not so much as to cause the drop in level youve described.

Inspect the heater core nipples and hoses, I think you'll see evidence of a leak.
Or add UV dye to the coolant, then examine under Blacklight.
* * *
A small nick in the alternator pulley will only affect the edges of the belt that it contacts; frankly, I can't picture where the nick is, but it certainly has the possiblity of damaging the new belt.

Could a pebble have caused the nick?
Could have, but that is a loooonnnnng distance above the road surface.
Could a road pebble have gotten lodged in the belt during its lower travel, then ridden the belt to the alternator pulley whereupon it caused a nick? Anything's possible.
Doesn't really matter IMO; either the nick doesn't contact the belt so it's not a hazard, or it does (or might) and should be filed smooth to prevent damage to the belt.

Does a spot of welded-on rubber on the tensioner idler pulley bode ill?
You bet!
It indicates that at some point in time, the belt was loose enough to slip against this pulley and cause enough friction to melt the rubber.
The pulley might have been jammed causing too much friction for it to spin, or the tensioner might have been jammed preventing adequate tension, or this might be the result of the extremely-frayed belt just before its absolute demise when you found it (a frayed belt has virtually no tension, so it's likely to slip against any pulley).

I would definitely investigate that tensioner further, and replace it if all's not well or if it's over about 50k miles old.

Good luck,
-Rick

[jessman1128]

Wow...I thought I had replied this to weeks ago. Apparently I didn't. I think I'm losing my mind...

Thank you for the informative, detailed post; it was greatly appreciated.

For various reasons (mostly weather- and medical-related) I haven't done anything with either of these issues since I first started this thread. I plan on investigating the tensioner very soon - I think/hope spring is finally on the way here in Michigan, so hopefully in the next week or two I will be checking out the tensioner.

The coolant leak is getting worse. I tried reading up on the heater core and related parts, but was unable to locate one key piece of info - namely, where the heck is the heater core? I've figured out that it is apparently behind the lower dash somewhere, but is it the driver side or passenger side?

The leak no longer occurs just when the heat is on (if it ever did - it's very possible I just imagined this, since at the time I was driving with the heat on 90%-95% of the time). For example, today I made the hour-long drive to work without ever turning the heat on. A few minutes after parking the car, a small puddle of coolant had collected under the car. I peered underneath the car and watched it drip for a few minutes - I'm not sure yet exactly where it's originally leaking from, but the final drip location appears to be around the front edge of what I believe is the transmission fluid pan. It's towards the rear of the engine and towards the driver side. Or would that be the oil pan? My knowledge of the parts on the underside of the engine compartment is virtually non-existent. I'm pretty sure it's the transmission pan, based on its shape. Any ideas what's above that could be leaking coolant? I'm going to pull out some engine diagrams later tonight and see if I can find anything that way - probably not, but won't hurt to try. Would this location match with it being a heater core problem? Or is the heater core on the other side (passenger) of the engine?

[arthurgoboom]

The heater core is basically in the center of the car. Leaking coolant could come from several places in the location you're referring to, since the water pump is located on the backside of the engine, and there is a sealing surface from the block to the water pump cover, pump cover to pump, and the thermostat housing. There's also a pipe coming off the water pump cover going toward the driver side that connects to one of the heater hoses. There's a quick disconnect fitting on that with 2 o-rings inside, and then the hose clamps onto the q/d fitting. Also the other heater hose runs through this area. Unfortunately it's damn near impossible to see in there to diagnose it without removing the exhaust manifold.

There's a weep hole in the water pump, but when mine failed and leaked from the weep hole the coolant ran down the passenger side subframe/A-arm. I found I could wrap my hand down behind the engine (from the top) and touch the bottom of the water pump to feel for wetness to confirm where my leak was coming from. Maybe you can do the same to feel what's going on.

[Matt95GT]

Sounds like either the heater core is leaking, or both heater core and something else (water pump, coolant outlet in from head, hoses). Coolant manages to run all over the place, so you're going to have to get under there to investigate before making any solid conclusions.

The heater core is underneath the center area of the dash. The OEM one is a timebomb with its plastic side tanks. It will leak externally via AC condensation spout in the firewall.

Here:
http://www.gaownersclub.com/forum/showthread.php?t=29080

Some pics when I did mine (your dash and center console differ, but otherwise same heater core and HVAC arrangement from 92-98)...
http://www.gaownersclub.com/forum/showthread.php?t=85241
http://www.fazeshift.org/pics/thumbnails.php?album=177

[jessman1128]

The heater core is basically in the center of the car. Leaking coolant could come from several places in the location you're referring to, since the water pump is located on the backside of the engine, and there is a sealing surface from the block to the water pump cover, pump cover to pump, and the thermostat housing. There's also a pipe coming off the water pump cover going toward the driver side that connects to one of the heater hoses. There's a quick disconnect fitting on that with 2 o-rings inside, and then the hose clamps onto the q/d fitting. Also the other heater hose runs through this area. Unfortunately it's damn near impossible to see in there to diagnose it without removing the exhaust manifold.

There's a weep hole in the water pump, but when mine failed and leaked from the weep hole the coolant ran down the passenger side subframe/A-arm. I found I could wrap my hand down behind the engine (from the top) and touch the bottom of the water pump to feel for wetness to confirm where my leak was coming from. Maybe you can do the same to feel what's going on.

Thank you for your reply. I had the leaky water pump issue previously, and got it replaced last year at a local GM dealer, along with the thermostat and timing chain. I had dealt with the water pump leak for quite some time before finally getting it replaced - which is why this new leak is so frustrating for me. I had hoped to get a lot more leak-free time out of the car than I did. Anyway, I know this isn't a water pump issue, because I'm extremely familiar with the location of a water pump leak.

I may have to end up taking this back to a shop to have them figure it out. Really don't want to spend the money, but it sounds like tracking this down could be a pretty in-depth job for a relative amateur like myself, and it will probably be quite awhile before I'll have enough free time to tackle it - and if the leak keeps getting worse, I don't think I can afford to put it off for that much longer.

[rixGAphx]

The rear face of the engine block (between the engine and tranny) should have a 'freeze plug' in it.
They rust and leak.

Above that point is the actual cylinderhead; a blown headgasket can also leak to this location, but that would prolly have other significant symptoms.

As AGB stated, the core is just about in the middle of the firewall.
The heater hoses crosing that space would be the *most logical* candidates for leakage, since they are only expected to last about 5-8 years but are frequently neglected (forever) since they are such PITAs to access.

[jessman1128]

The rear face of the engine block (between the engine and tranny) should have a 'freeze plug' in it.
They rust and leak.

Unfortunately, I do believe you are correct. I finally made time to investigate the leak further this past weekend. I spent a couple of hours figuring out how to get to the heater core mixed with wedging myself under a non-jacked car to try to visually narrow down the location of the leak, only to then discover that I could see the two heater core hoses through the top of the engine compartment. I felt the entire length of the hoses - no leaks. And when I saw where they disappeared into the firewall I knew it wasn't the heater core, because the leak is most definitely farther forward than that. I could have saved myself a couple of hours had I looked for the hoses from up top before doing anything else. Oh well. You live, you learn. Or so they say.

I traced each coolant line as far as I could see/feel, without finding the leak or any evidence of it. The location where it ultimately drips from - the rear edges of the tranny pan - leads me to believe that it probably is the freeze plug.

I've read various opinions on replacing leaky freeze plugs, and most of them sound downright awful. Not because the freeze plug itself is hard to get out, but because you typically have to remove the engine to have enough room to drive in the new freeze plug.

Anybody know exactly where the freeze plug is at on this engine, and if it will require removing the engine to replace it? It's the 2.4L LD9 engine. Or are there multiple freeze plugs?

Also, it doesn't sound like the type of part that can simply be patched/repaired, correct?

[Matt95GT]

You need to inspect better before concluding it is a freeze plug. (I've never heard of anyone having a 2.4 with leaking freeze plugs, but this is common on the V6)

First of all, I still wouldn't rule out heater core. It will not leak from the hoses on the engine side of the firewall. The coolant will drain from the AC condensation drip spout, which is more to the passenger side from the hoses. The fact that you're smelling coolant in the car still makes this the top suspect. (or your primary leak is somewhere else but the heater core is starting to go too)

Other areas to check based on your description... coolant outlet (aka "thermostat housing" even though there's no t-stat there) that sticks out of the drivers side of the heard, or the water pump.

[jessman1128]

You need to inspect better before concluding it is a freeze plug. (I've never heard of anyone having a 2.4 with leaking freeze plugs, but this is common on the V6)

First of all, I still wouldn't rule out heater core. It will not leak from the hoses on the engine side of the firewall. The coolant will drain from the AC condensation drip spout, which is more to the passenger side from the hoses. The fact that you're smelling coolant in the car still makes this the top suspect. (or your primary leak is somewhere else but the heater core is starting to go too)

Other areas to check based on your description... coolant outlet (aka "thermostat housing" even though there's no t-stat there) that sticks out of the drivers side of the heard, or the water pump.
Thank you for your reply. I won't argue that I need to inspect better instead of just assuming it's a freeze plug. However, I'm quite sure it's neither of the two items that you described, for the following reasons:

I am very familiar with the location of the water pump/t-stat, having had that replaced last year due to a severe leak. The location of the current leak is nowhere near close enough to the water pump for that to be suspect, unless the leaking coolant is somehow traveling sideways halfway across the engine before letting gravity pull it down to the ground. Possible? I suppose. I've already visually inspected that side of the engine as best as I could, but I'll double-check it again just to be sure.

I don't know exactly where the AC condensation drip spout for the heater core is located, but I'm assuming it's attached to the heater core. I can't see the heater core from the engine compartment, because it's on the other side of the firewall. However, there's a fairly significant amount of space between the firewall and where the heater core hoses run into the engine area - empty space that I can see down to the ground through - and the coolant leak is somewhere to the front of this empty space, which I believe rules out the heater core entirely.

[Matt95GT]

Yea, I would still double check everything - leaking fluids have a funny way of running all over the place. Even under the car on ramps I had a difficult time finding the source.

The condensation spout is right next to the AC lines going through the firewall. Here's a pic from the inside... note the heater core lines (drivers side) in relation to the AC lines (passenger side... blue R-134 tag)...
http://fazeshift.org/pics/albums/userpics/01-12-08/IMG_1720S.jpg

Sounds like water pump can be ruled out, but I would inspect that water outlet. Many owners here have reported leaks from them recently... and it is yet another weak plastic part in the cooling system. :doh:

[jessman1128]

I have been able to confirm that the coolant leak is not from the heater core or water pump or anything attached to them. It appears to be leaking from the engine itself. I jacked the car up today as far as I could with my old scissors-style jack that is partially stripped (meaning I couldn't get the car up very high) and crawled/inched my way underneath it as far as I could. I couldn't get under it far enough to be below the leak (probably good - as much as it's leaking now I would have only received a faceful of coolant for my troubles) but I did narrow down the location. The leak is dripping down from between the oil pan and transmission fluid pan. I reached my hand up in between them and blindly felt around for a minute or two, but didn't accomplish anything other than getting coolant and grease all over my arm. I'm including a picture below. The picture is from the front of the car facing towards the rear - the edge of the oil pan is at the very top of the picture - the transmission fluid pan is behind that and you can clearly see the coolant dripping off of it. Somewhere up in the visible gap between the oil pan and the transmission fluid pan is where the leak is originating.

Anyone familiar with the lower part of this engine block? Could I be looking at a corroded freeze plug or engine block drain plug? Or is this probably much more serious, like a leak in the cylinder head or something?

I think I'm going to take it in to the shop this week and see if they can pinpoint the source of the leak without charging me an arm and a leg and then see what I'm working with. If anyone has any ideas based on this new info/picture I'd appreciate hearing them though. Thanks!

http://i6.photobucket.com/albums/y217/jdolson37/car/CoolantLeak002.jpg

[gt00]

I jacked the car up today as far as I could with my old scissors-style jack that is partially stripped (meaning I couldn't get the car up very high) and crawled/inched my way underneath it as far as I could.NEVER , get under a vehicle without jack stands , using the jack only is extremely dangerous . :eek:

[jessman1128]

NEVER , get under a vehicle without jack stands , using the jack only is extremely dangerous . :eek:
You are correct. It was quite foolish of me. I had intended on putting it up on my jack stands, but when I realized my jack was too messed up to get the car high enough for that I foolishly decided to inch under the car as it was to get a better view. In hindsight, the fact that I was using a malfunctioning jack probably made it all that more foolish. Thankfully nothing tragic happened, but I'll make sure I don't do it again down the road. I tossed out the jack as soon as I was done, so now I have to buy a new working one so I'll be able to use my jack stands again next time.

[rixGAphx]

You are correct. It was quite foolish of me. ....You roll-over too easily.

This is the internet, where you're supposed to whine defensively and piss-off the audience until we decide to never help you again.



The rest of us never got a chance to answer "x2" to gt00's admonition.

:D :D
* * *

Isn't that wet location almost EXACTLY behind where a WP/t'stat leak would drip/spray water?
I dunno, never worked on a 4-cyl GA.

Personally, I would:
* Put my ramps in the trunk and go to a coin car wash, and safely crawl under there and spray it as clean as possible.
* Add some universal UV dye to the coolant system.
* Get a flashlight, couple mirrors, UV/Blacklight.
* Go to a local shop and ask to have them lift the vehicle so I could get excellent viewing angles. Mebbe $20?
Ramps *might* get you enough clearance to do this inspection in your driveway.
* Inspect for the tell-tale glow of the dye.

Good luck,
-Rick

[arthurgoboom]

There is a steel pipe that comes off of the water pump cover that runs across from passenger towards the driver's side, which connects to the return (?) hose from the heater core. Not only is it a steel pipe which has the potential of rusting out, but it also has a quick-disconnect fitting on the end where the heater hose connects. This Q/D fitting has O-rings in it that could potentially fail, especially if the joint is disturbed after 10+ years of service.

The pipe runs right above the gap between the engine and transmission, but I don't think you can see it from below. The only time I could really see it is when I had the water pump cover off during my water pump change. When I did mine I first took the clamp off the heater hose and removed the hose from the barb, then disassembled the Q/D fitting and put new O-rings in it (from an assortment kit I have). There's 2 O-rings and a spacer ring that goes between them. Then I used some steel wool to polish the nipple on the steel pipe until no old rubber/crud remained. I lubed the O-rings with a little engine oil and put it back together, then put the new heater hose on the plastic nipple once it was installed in the car.

Not sure if that's your problem, but it's in the right area, and if it is, well there's the repair procedure.

[jessman1128]

You roll-over too easily.

This is the internet, where you're supposed to whine defensively and piss-off the audience until we decide to never help you again.



The rest of us never got a chance to answer "x2" to gt00's admonition.

:D :D
<chuckles>


Isn't that wet location almost EXACTLY behind where a WP/t'stat leak would drip/spray water?
I dunno, never worked on a 4-cyl GA.
Of course it isn't! It's dripping a good 6-12 inches away from where it dripped last year when the water pump seal failed.

:bash: :bash: :bash:

I've never actually seen the water pump on the car - just a few diagrams from repair manuals. I just pulled up those diagrams again and looked at them a little more closely. I don't have a single diagram that shows the location of the water pump, oil pan, tranny pan, etc. However, based on trying to piece together several different diagrams it would certainly appear that perhaps the water pump is actually a possibility.

Tomorrow morning I'm going to call the dealer that replaced the water pump and make an appointment. If I get super-lucky it will be the water pump and they will make the necessary repairs for free. (I'm not expecting this to be the case though.)

I absolutely despise spending money to pay somebody else for car repairs. However, I now know that whatever this problem is it's not something I'll be able to fix myself. I'm extremely limited in what I can do myself if it involves working from underneath the engine. So since I know I won't be able to fix it myself I might as well just ask the shop to pinpoint the source of the leak.