I have a 1997 sunfire and the motor went out, so i got an engine from the next model year up. Turns out i had to get a new head for it cause of a egr problem. Then turns out that the compression is too high because of the car being made in canada, and its causeing the car to ping and detonate. Is there any way that i can get the compression down with out having to get a new engine again. already dropped $2000 on it.
well we had to put another head because the egr valve on the older models up to 97 are different from the 98+. the canadian version of the engine has some sort of weird thickness of head gasket so this causes the compression to be high.
Thats incorrect, the compression is no different, the headgasket is no different, its all the same. Call GM and ask for the head gasket thicknesses, then call a canadian dealer and ask, they are exactly the same. Like I said, there is no difference between a canadian engine and an american one. Same down to the fluids they use.
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my mechanic said that the problem was with having to use a head from the model year of the car 97, with the newer engine. he was like that the ports for all the american engines he tried were different and that the engine from canada had a different egr setup than the american ones. but besides that are there anyways that I can lower the compression?
I understand what he is saying but that doesn't explain why the compression is so high. I'm more trying to find out what I can do to decrease the compression. thanks for the replies so far.
that's what I've been running. would fuel additives do anything? what about retarding the timing?
also he said that only race gas would be a high enough octane and the car is not meant for race gas.
Martin Seay wrote:also he said that only race gas would be a high enough octane and the car is not meant for race gas.
Maybe if you aren't running a headgasket at all. 99+ ld9's have no EGR and 9.7:1 CR opposed to your old which did have an EGR and 9.5:1 CR (both based on standard .043" head gasket thickness). That isn't enough of a difference in compression to even consider mid grade gas. I would also strongly advise you to get other opinions, because it sounds like the guy supplying you with all of this info has no clue what he is talking about. Are you using your old ECU? I assume so since you are talking about using the EGR. If so, are you using the injectors and knock sensor off of your old motor? Because you have to.
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"Youth in Asia"...I don't see anything wrong with that.
You are talking about the 2.4 TC and not the 2.2L OHV, right?
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"Youth in Asia"...I don't see anything wrong with that.
its *the 2.2. so upgrade the ecu and knock sensor.
On the 2.4L you have to use your old injectors and knock sensor. I don't know much of anything about the 2.2L OHV however. Sorry.
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"Youth in Asia"...I don't see anything wrong with that.
ok. what tools do I need?
a compression tester. its very easy to use. its a gauge that has a hose that screws into a spark plug hole, with a peak-hold valve. you take out a plug, screw this in, then have a friend start the car. let it run until the needle on the gauge stops going up, then stop the engine, and read the number on the gauge. do this for all 4 cylinders. then come back to us with the results.
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I'm sorry, but your mechanic doesn't know his ass from a hole in the ground if those are the lines he's feeding you. If its "canadian", and thats the only reason it doesn't run right, then how would canadians run thier cars? I'm pretty sure all canadians aren't running around with race gas in thier cars.
The only way's to decrease compression:
1. Get lower compression pistons
2. Get a thicker head gasket (this only MARGINALLY alters compression).
3. Mill out your stock pistons (NOT recommended).
Second, a compression tester will only tell you your dynamic compression, and its use is to let you know if you have ring, piston, or head gasket damage. You do not use a compression tester while the car is running, it is very important that you disable the ignition system to use a compression tester, you don't run the engine till the needle stops moving, you just crank it until it stops moving.
I think your mechanic is feeding you a LOT of bull@!#$, take it to somebody qualified to work on cars.
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Well first thing first. Why use the 2200 on the 2.2? Why not use a 95-96 head? I don't know the difference between the 2200 and the 2.2 head but I don't think they are exactly the same. Also, you are mixing 2 engines hence why you may have 2 different gasket thickness.
Your "mechanic" is not a mechanic at all. I'm suprise he knows witch way to turn the bolts.
Gilles
2.3 Ho
I didn't saw right the first time but still, how come the head would be different? Tell him to order the right head and to look at casting number.
Gilles
2.3 Ho
going to get the tester tomorrow. just to explain basically he put an egr head from the model year of the car which is a 97 on a newer model motor which is the 98-02 2.2. just for those who don't fully understand. should have just found the same model motor. the new motor only had 5000 miles on it that's why I jumped on it.
The older head on the newer motor is going to cause the compression to be higher, i think it was OHV NOTEC that explained this to me.
The engines from 95-97 and 98+ are different. I dont know if its possible to put the head from the old model on the new motor, but if thats what you did, then you need to change it to a 98+ head. I think the number NOTEC gave me was like 13:1 compression is what i would have made if i bought the ported head he was selling from a 95-97 motor and put it on my 98+.
If thats the case, Swap out the head for another 98+ head, and problem solved, wont take more than half a day and you could get one from a junkyard for probably cheap.
good luck
