Tapping And bogging Down

[Phreak5758]

Whenever the car is running it is making a tapping noise.... Similar to what you would hear if the car was real low on oil. I'm not sure what it is haven't had the thing apart to check, looks kind of daunting if you ask me lol.

My other problem is if I try to take off at 1/4 to 1/2 throttle the car bogs down like it is getting ready to die but if I stomp the gas it smooths out and runs fine. It only does this until the motor is warmed up pretty good.

Just replaced Fuel Pump, Plugs, Air Filter, Heater Core, Thermostat, And soon to be replacing waterpump Seals

105k Miles on it.

[RomeoGAOC]

the problem with the engine bogging down is probably your coils and/or coil housing.....dont worry its happened to us all

[p8ntman442]

the tapping could either be your lifters not having oil due to a stuck check valve in the block letting the oil drain back when the engine is off, or it could be the fuel injectors clicking. the bogging down could be from either of these or as stated, most likely it is the idi system. (they suck) Try to pinpoint the sound of the tapping by holding a large screw driver against the cam towers, and holding your ear against the handle, or use a mechanics stethascope if you have one. Let us kn ow and we can further advise you.

[Gmuze63]

I had the same problems occur simultaneously. Thought it was clogged fuel injectors but it turned out to be my Oil Pressure Switch. Unfortunately, I drove it for about a week or so before repairing. Mechanic says I may have done some permanent damage to the engine. He replaced the switch, and car runs fine, but the tick remains. From what I read here, tick may be harmless, (sticky lifter maybe), but it should quiet down as the car warms up, but so far car is OK. I'll keep you posted. Good Luck - hope this helped!

[gtzpower]

Originally posted by Phreak5758
My other problem is if I try to take off at 1/4 to 1/2 throttle the car bogs down like it is getting ready to die but if I stomp the gas it smooths out and runs fine. It only does this until the motor is warmed up pretty good.


There was a technical service bulletin about this for the 90 quad, and GM issued an updated prom to resolve the issue. I guess if there was a decent temperture change that occurred since you shut the car off, this was the result because the ECM thought the current air temp = the air temp when you last turned the car off. But, once you hit closed loop (once the car warms up), it reads the actual current temp. and starts runing right. Might check with gm to see if that TSB applies to your year.