Lim?

[mattcow]

For a couple of months now I've been toping off my coolant every few weeks and noticing some coolant on the side on my engine (sitting in a puddle next to the tranny) and some oil in the coolant reservoir….so I was expecting a LIM gasket replacement soon. I was hoping to make it to spring when its warm but the "top ups" on the coolant have been getting more frequent.

I started searching and found that oil in the coolant reservoir doesn't signify a LIM:
http://www.gaownersclub.com/forum/showthread.php?s=&threadid=68063&perpage=20&highlight=oil%20coolant%20tank&pagenumber=1

but my car has a significant amount of oil (brownish floaties and slim) in the reservoir. In fact I noticed this in the summer and did a coolant flush but its back now which seems to be too quick for it to be normal.

So do I in fact have a LIM problem or is it something else?

[00SilverGA]

I can't say for sure but chances are it is the LIM leak.

[rixGAphx]

Forget the stuff in the reservoir.

Let's just find your 'Disappearing GM Coolant'

How much coolant are you losing: 1 cup (8 oz/250ml) /week?
Are you getting a puddle on the floor of your usual overnite parking spot?
What type/brand of antifreeze did you use after the flush?
Take a pic of "...coolant on the side on my engine (sitting in a puddle next to the tranny) and post here.

Replace your pressure cap if it's not new, ~$12 at Checker.
Only tighten as much as an average woman can easily do one-handed.
Overtightening will cut or distort the rubber sealing ring, which will allow coolant to escape as vapor.

Examine all the usual leak locations for liquid/tear stains, and clean the areas for observation during the next 2 weeks:
* Both ends of both heads.
* Upper rad hose connection at t-stat housing.
* Driverside plastic rad tank, above and below the uppre rad hose neck (looking for bulge or hairline crack).
* Hose connections at the heater core (looking for hairline crack in the hose nipples).
* Waterpump weep hole.

Get a bottle of 'All-in-One' automotive UV dye, and add to coolant.
http://www.partsamerica.com/ProductDetail.aspx?categorycode=3569&mfrcode=EVP&mfrpartnumber=0565

Drive around for a week, keeping an eye on the coolant level and topping-off as required; keep a log.
Get a UV blacklight (true fluorescent 'black light', not the $4 incandescent bulb from Walgreens or such).

Re-examine all the 'cleaned' possible leak areas, using the blacklight.
Report back here.

Hope this helps,
-Rick

[coupe]

Its an LIM leak, dont kid yourself

[mattcow]

Every time I noticed my low coolant light go on (hills and accelerations) I would fill the reservoir back up to the max line so however much that is...maybe 2 to 3 cups every 2 weeks.

Only notice the coolant accumulating on the engine twice but it is always wet.

I never see a puddle on the ground so it would seem that it happens driving only.

I replaced the reservoir cap during my coolant flush in the summer due to a broken o-ring.

I flushed and replaced the coolant with Prestone Dex-cool but the previous owner had green stuff in there with a little orange in the reservoir tank.

I'll get some pics tonight

[sunrunner_pei]

With coolant on the transmission housing, it's almost certainly the LIM gasket. Welcome to the club.

[rixGAphx]

Originally posted by coupe
It's a LIM leak, don't kid yourself.I agree, the probability is 98% that it's a LIM gasket.

But it's HIS $750US we're asking him to shell-out.

And I would rather have him jump thru some hoops and spend $12 + $7 to confirm it;
Than have him pay for the work and discover (on the 2% off- chance) that the underside of the $15 upper rad hose was leaking at the t-stat neck.

I've jumped to enough (wrong) conclusions to be conservative with my recommendations to others, even if don't always follow my own advice.

And one thing concerned me about his recent activities, where the car is using more and more coolant:
He's obviously removing the cap more often, and that seal may be absolute toast by now.
It's amazing how much water, in cc's or tablespoons or whatever, escape as invisible steam thru a tiny passage.

[pontiac3100]

hey rixgaphx...you mail box is full
sorry to high jack

[rixGAphx]

The crud in the reservoir is *prolly* the sludge that's often associated with mixing DexCool and 'conventional' antifreeze, plus some of the minerals that the flush partially-dissolved.

[rixGAphx]

Originally posted by pontiac3100
hey rixgaphx...you mail box is full
sorry to high jack Yeah, I thought if I just let it get full you would stop bothering me.







:D :D :D :D :D :D

j/k, couldn't resist

[coupe]

Originally posted by rixGAphx
I agree, the probability is 98% that it's a LIM gasket.

But it's HIS $750US we're asking him to shell-out.

And I would rather have him jump thru some hoops and spend $12 + $7 to confirm it;
Than have him pay for the work and discover (on the 2% off- chance) that the underside of the $15 upper rad hose was leaking at the t-stat neck.

I've jumped to enough (wrong) conclusions to be conservative with my recommendations to others, even if don't always follow my own advice.

And one thing concerned me about his recent activities, where the car is using more and more coolant:
He's obviously removing the cap more often, and that seal may be absolute toast by now.
It's amazing how much water, in cc's or tablespoons or whatever, escape as invisible steam thru a tiny passage.


Im definately not asking him to blindly spend $750. What i am getting at is is i dont want to see him try to kid himself into thinking its somethings else. He could spent a small fortune replaceing all the little things and in the end still have to spend $750.

All he really needs to do is take it to a reputable shop, they will confirm where the leak is coming from.

[mattcow]

Driver side...coundn't get a good shot of the pas. side

[mattcow]

another angle....

[mattcow]

resevoir...

[mattcow]

no milkshakes....

[mattcow]

this sludge doesn't look good.....any idea if this is related?

[mattcow]

If I do replace the LIM gasket I will do it myself so it won't hurt the wallet as much....just don't want to freeze my ass off for nothing

[thegrimone]

find a heated garage man its the only way this time of year, if I can get the rest of the parts from advance auto tomorrow I'm going to try to do mine this weekend.

[bhermis]

Hahaha wow, those pictures look familiar...

I just bought everything and i'm going to start this weekend on my 2000 gt 3400

I decided to go with the kit from NAPA instead of the felpro. It included more gaskets.

I figured that for a first timer working with a friend we can take it down and reassemble in 8 hours is that resonable?

I havn't gotten to it yet but i'm wondering about the push rods. Is it absoluetly neccessary to remove those to get to the LIM gasket?

Also I think I'm going to flush the system first using a chemical flush, then do the job then refill with universal long life from Advance.

Any thoughts or comments. I'm going to use this walkthrough.

http://www.grandamgt.com/forum/showthread.php?t=60868

[rixGAphx]

Mattcow:

The sludge in the coolant cap looks more-or-less 'normal' and nothing to be concerned about IMO.

The gunk on the oilfiller cap and PCV valve are also 'normal', resulting from hot water vapor in the crankcase air condensiong on these cold pieces, then 'homogenizing' with the oil.
Just clean it off with a papertowel and replace the devices.

The pic of the head end does seem to indicate the stain could be coolant coming from the LIM-to-head interface.
It's hard to tell, since it might also be oil leaking out the end of the valve cover.
The upper rad hose at the t-stat housing seems in good shape, as opposed to being a source of the 'wetness'.

So, it's looking more and more like the LIM gasket is the culprit.

Does the pressure cap hold pressure, and is the WP weep hole only showing a minor stain?
These would be the last two 'leak points' to confirm.
* * *

Brian:

8 hours for two wrenchers is fine.

Yes, teh pushrod-removal procedure is necessary, since the pushrods thread thru the LIM gasket; hard to describe, but you'll see what I mean as soon as you remove the LIM.

Good luck,
-Rick

[HeyDace]

Originally posted by bhermis
Hahaha wow, those pictures look familiar...

I just bought everything and i'm going to start this weekend on my 2000 gt 3400

I decided to go with the kit from NAPA instead of the felpro. It included more gaskets.

I figured that for a first timer working with a friend we can take it down and reassemble in 8 hours is that resonable?

I havn't gotten to it yet but i'm wondering about the push rods. Is it absoluetly neccessary to remove those to get to the LIM gasket?

Also I think I'm going to flush the system first using a chemical flush, then do the job then refill with universal long life from Advance.

Any thoughts or comments. I'm going to use this walkthrough.

http://www.grandamgt.com/forum/showthread.php?t=60868


Wow, to much info...brain hurts.

You did good buying the better gasket set. Forget the acetone, use 80 grit sandpaper and razor blades to clean the mating surfaces and brake clean to duoche them off. Don't f*ck with the fuel rail. Leave it on the lower intake and just unbolt the fuel line retainer bracket after disconnecting the fuel lines. Under the bracket that retains the fuel line bracket is a nutted stud that needs to be loosened in order to remove the intake to heater core tube. Its a bitch and probably the hardest part of the job.
After that it is pretty much text book. And yes, you need to remove the pushrods to remove the intake gaskets. Just keep them in order and if you get screwed up remember that the LONGER pushrod is exhaust and the SHORTER is intake, doesnt matter if it is matched to the same cylinder (well in my book anyway).

'smatter o'fact, I just did an intake on a '01 Lumina, 3.1 today.
Pays 5.5 hours and I bet another tech that I could do it in less than 3...2 hrs and 45 mins later I was $50 dollars richer and the engine ran great.
A little word about "burping" the cooling system. I'm sure you've heard stories about blown headgaskets and cracked heads after LIM repairs and this is why.
I've seen a lot of techs fill the system without cracking the bleeders first, then just run the shit out of the engine till it almost redlines. They shut it down and of course the ever faithful geyser of coolant shoots out of the radiator. Then they fill it again and run it with the bleeders OPEN!
While one bleeder is expelling coolant, the other is sucking in air. You may as well chase your tail. You will NEVER get the air out that way.

This is the procedure (my procedure) never fails:

Open both bleeders and fill the radiator until the coolant begins to flow from the bleeders. Close the bleeders and idle the engine @ 1500rpm for at least 10-15 mins. Watch the temp. Shut it down and wait a min, then crack the bleeders and allow the air to escape untill you see coolant again. Close the bleeders and top off the coolant. Run another 15 mins @1500 rpm, shut it down and crack the bleeders again until you see coolant flowing.
Top off and run the engine at 2500 rpm for 1-2 mins (you should be getting heat through the vents now) and the gauge should be at normal operating temp.
If you have the time shut it down, cap it, fill the overflow and let it sit for an hour or so. That allows most all the air to migrate up and out of the radiator fill and as it cools it will pull coolant from the overflow (providing you radiator cap is good).

It works for me and can be done in a half hour.

[rixGAphx]

Originally posted by HeyDace
...A little word about "burping" the cooling system.

Open both bleeders and I've only ever worked on one 3.1, my '96.

It only had ONE bleeder TTBOMK: Atop the vertical tube on the rear of the waterpump.
There was a transfer tube from that vertical tube to a bleed port in the top of the t-stat outlet neck.

Isn't it this way for ALL GA 3.1/3.4's?

I know of at least one GM minivan V6 without this 'bleed transfer tube', and it had a second bleeder at the t'stat.
Are *some* GA's like this??

Or is there actually ANOTHER bleeder??

-Rick

PS: Shouldn't GM have put a bleeder in the top of the radiator??

[mattcow]

Rick, the pressure cap does hold pressure and there doesn't seem to be any significant staining around the water pump weep hole.
Any idea on how long I can let this go for before I fix it?

[HeyDace]

Originally posted by rixGAphx
I've only ever worked on one 3.1, my '96.

It only had ONE bleeder TTBOMK: Atop the vertical tube on the rear of the waterpump.
There was a transfer tube from that vertical tube to a bleed port in the top of the t-stat outlet neck.

Isn't it this way for ALL GA 3.1/3.4's?

I know of at least one GM minivan V6 without this 'bleed transfer tube', and it had a second bleeder at the t'stat.
Are *some* GA's like this??

Or is there actually ANOTHER bleeder??

-Rick

PS: Shouldn't GM have put a bleeder in the top of the radiator??

Right, one bleeder on the closed systems, later model GMs. But the premise is the same. Open then fill.

[mattcow]

To try and push my LIM gasket repair to the spring, I tightened up the one bolt I could see on the LIM in the same corner as my leak (front driver-side corner). The bolt was finger tight but by removing the PCV and rotating throttle out of the way I managed to get a wrench on it. Its only been two days but there has been no leaking so far.

[bhermis]

I removed the connectors from the fuel rail but their is a hard line that runs inside of the fuel rail for about 3 inches. You can't pull the LIM straight up. I had to slide the injectors out and then take the rail off and then the LIM off. Pissed me off cause I didn't want to mess with the injectors. Now that they are out I'm going to replace the orings. Can i clean the injectors somehow? What should I use?

Also how tall should the bead of silicon be on grooves below the LIM?

[rixGAphx]

Originally posted by bhermis
I removed the connectors from the fuel rail but there is a hard line that runs inside of the fuel rail for about 3 inches.
You can't pull the LIM straight up. I had to slide the injectors out and then take the rail off and then the LIM off. Pissed me off cause I didn't want to mess with the injectors.
Now that they are out I'm going to replace the orings.I don't know what "hard line" prevented 'straight-up' removal of the LIM.
Do you mean the cross-over tube at the passenger end of the rail? That transfers fuel from the rear rail to the front rail, so you remove it intotal with the front and rear rails.

First you disconnect the fuel supply (driver side, rear rail) then the return line (driver side, front rail, at underside of FPR).

If something else is in the way, you unbolt it and remove it.

But in any case, you don't remove the injectors from their connectors to the rail, then remove the rail.
Rather, you remove the entire U-shaped RAIL ASSEMBLY, with injectors attached, from the LIM; then remove the injectors from the rail if neceesary for replacement.

You kinda 'rotate' the entire rail assembly and 'rock' the injectors in their LIM sockets, to pull out the rail (with attached injectors).

Installation is reverse.

Can i clean the injectors somehow? What should I use?Not effectively.

The needle inside the injector is closed against the seat.
It's the seat you want cleaned of built-up 'varnish'.

Best thing to do IMO is take them to a shop that advertises as FI specialists, and pay them to pressure clean them (by electronically opening them and forcing cleaner at high pressure thru them).

I dunno the cost.

Also how tall should the bead of silicon be on grooves below the LIM? I dunno.