Hey, my name is Cory. I drive a 1984 Olds Firenza.
I was driving home the other night and i lost my throttle response. When i pulled over, the car died. I can't get it to start, and I recently figured out why. I did a compression test and the numbers are as follows:
Cylinder # 1 = 125 psi
Cylinder # 2 = 15 psi
Cylinder # 3 = 20 psi
Cylinder # 4 = 30 psi

What could cause this? Thanks a lot everyone.
Cory

First, check your timing belt/chain.

Assuming it's good, it's probably a head gasket.

Were you driving normally? You didn't rev it super high and float your valves did you? I'm saying this without knowing if your car is interference or not.

Did the car overheat or did you see smoke out the tailpipe? Check the coolant and oil and see if they're mixing at all.

Brian

Not much information to work with....

As a "guessing game", I'll speculate...

You were travelling at high speed...

Then had to jam on the brakes...

This broke the crankshaft...

Rapid decelleration of an engine can also break

connecting rods...

If you broke the crankshaft, the block may still

be salvaged...

And exactly how many panic stops from high speed do you know of breaking a crankshaft ? Besides if the crank were broken how did he run a compression test ? If the crank broke the pistons ain't gonna move and you won't get any compression.

Now which engine do you have? If its the 2.0 it has a chain and its doubtful it jumped time. True not impossible but doubtful. If its the 1.8 OHC motor then that has a belt and its more likely to have lost a tooth or two and lost timeing. I'd check the belt first if you have the 1.8. How many miles are on the engine as timeing belts rarly can go beyond 100,000 miles and being an 84 I'd venture to guess your well over that mark. If the belt checks good or its the 2.0 look to your head gasket as being blown.

Which engine do you have?




Semper Fi SAINT. May you rest in peace.

I have the 1.8 SOHC TBI.
It's a non-interference engine, so the means that my valves should be okay. As soon as i get the chance, i'm going to put some oil in the cylinder and check if that helps, if so that should be the piston rings, right?
I'm thinking best-case senario, I just move the 1st cylinder to TDC on the compression stroke, and reset the timing.
Any other advice?
Thanks guys.
Cory

Well first off the one person above doesnt have a clue how a car works. High speed braking cant cause you to lose compression. Infact i doubt the above poster knows what compression in a cylinder is referring to. Some people on here just post to post, anyways on to your problem.

If a headgasket goes normally, now I say normally not alwyas though two cylidners side by side are very low. It could be your cause.

Also piston rings, can be the cause, and exhaust and intake valves, either broken, or the cam jumped a tooth, and they arent closing correctly.

Because your #1 cyl is fine, I doubt it is a timing chain/belt issue.

Because it happened, just suddenly, I doubt it is your rings, as they generally cause running problems over time.

It isnt your valves because all of your readings would be low, a chain jumping takes out all the valaves.

If your test was done correctly, I would be most likely correct to say your blew a headgasket. Because reasoning eliminates the other choices.






- 2004 Cavalier - 124k, owned since new

/\ I agree, If something happened all the sudden there is a good chance it's the head gasket.





You can't outrun the radio.

Holy Crap!! Rob you actualy made sence that time! I'm sending you a cookie in the mail as soon a s I get home.

I hope you know I'm just messing with ya man!

Cory just because its not an interference engine doesn't mean that if the belt slipped it would put the engine out of time. This would cause the valves to open and close at the wrong time causeing low compression. Besides checking the belt to be sure BEFORE you tear into the engine just makes more sence. Why do work that you may not have to.

Rob S, Chocolet Chip ok ?




Semper Fi SAINT. May you rest in peace.

Well, when I said "my valves should be okay" i meant "my valves should be not bent to @!#$." So should i just reset my timing and get a new head gasket? AI'm going to try the oil thing tomorrow. If that doesnt help, I'll know for sure.
Thanks everyone for your help, I'll keep you posted on how everything works out.
Can anyone recomend where to get nice cheap gaskets?
Cory

I doubt the cylinders are dry ( your oil thing ) Its more likely the head gasket but I said to check the belt cause I have heard of it happening before and it would be a bitch to pull the head if you didn't need to.




Semper Fi SAINT. May you rest in peace.

Well, I put a teaspoon of oil in each of my sparkplug holes, and re-ran my compression tests, and you guys were right, my piston rings are good. So that leaves me with head gasket or timing, right?
How would I go about checking the timing?
Thanks everyone.
Cory

Yup either one of the 2. To check your belt just crank the engine by hand and look for any missing teeth if they're all there then its deff the head gasket.




Semper Fi SAINT. May you rest in peace.

Well, Ive just decided to replace the timing belt and head/valve cover gasket. Might as well replace the belt while i have the head off. Any tips or tricks that anyone can suggest when replacing a head gasket? This is my first DIY head gasket job. If anyone lives in the Indianapolis area and wants to lend a hand tomorrow, feel free to give me a call 317-371-7918.
Thats for your help everyone, i appereciate it.
Cory

You should have a die grinder on hand. Also you need a tons of towels, to put in the cylidner holes. Dont let ANYTHING fall into the cylinders.




- 2004 Cavalier - 124k, owned since new

why would i need a die grinder?