What causes low compression?

 

I would honestly take your car to an Authorized 3rd party warranty shop, and see what they think. Maybe the dealership's just missing something obvious. What part of the US are you in? Someone might be able to recommend a reputable shop...

 

And did you just edit your post? I thought I saw a nice long description of the prioblem.... and now it's gone?

 

what year is the car and how many miles? have you had your valves adjusted at all?

 

perhaps you didn't check correctly?

was the engine at operating temperature? did you hold the throttle open all the way while cranking?

telling us what steps you took, and even your results, might help us help you.

 

Hello All,

Yes I did edit, due to another post I have listed.

Heres my story...
Im in Aliso Viejo, CA 92677
2000 Integra GSR
70k on it.
12/3 Installed new cap/rotor (Stock), wires (aftermarket), ngk plugs.
Towards end of Dec I got a CEL. CEL #72 or misfire in two.
Took it to a small dealership I dont usually go to.
They said I need a vavle adjustment.
Got that done.
Mechanic tells me after the work is done that he doesnt like my plugs....
1/04, CEL is on AGAIN! Took it back to Dealership, they tell me my wires are the issue.
Change my wires out, I get CEL on and off for another month.
Take it back, they do a compression test and show 1= 150, 2= 110, 3= 175, 4, 175.
They tell me they dont know why, but being that Im not burning smoke, not loosing oil, not getting bad milliage (280-260 a tank), thats its probably not the bottom end, they said it hardly is. Then they say they need to take the head off and check for a burn vavle, or seat issue, etc. Asking for 650.00 to tear it down, then that money could be used for the repair.

Now, heres the deal. My car runs fine, Im not buring oil, not getting bad milliage and the only issue is idle. Its not hitting on all 4 during idle. Its rough. Other than that, CEL is still on, and I can rev all the way to 8k with no issues. Like it was new ya know. It revs fine. Now I have taken care of this car. Its my second one and 5th one in my family. Ive only done air intake and rims, lowering 2 inches. Other than that, oil changes as needed, etc. Its clean and I baby it.

I just dont understand why I was orginally told vavle job needed to be done, which did make a difference, it was much more smoother after that, but I noticed that my Head seems MUCH hotter than it ever was to touch. MUCH hotter. Then they said its the wires, they swore it was the wires left and right. Telling me I need stock wires. Once I proved them worng there, now its my head.

I asked the mechanic straight up, if it could be a bad vavle job on his part? When it did it, he did it in like 2 hours with fans. He said no, that even if he did, I wouldnt be getting this low compression issue? Not sure, nor do I know about that statement.

So now Im sitting her looking into taking it to the dealership I purchased the car at (Tustin Acura) whom I called after I picked up my car from this dealership telling me its my head. The service adviser at Tustin said, you dont have low compression, I dont forsee that at all. He thinks Im getting the run around. He seems to think the vavle job or something else is the issue based off what I shared with him. So Im taking it them for another 85 bucks, just to get a second opinion. Its just getting old and Im running out of money to go back and forth, over what the issue is. I just want the root cause and I want it fixed.

Also, once I reset the CPU, I dont immediatly get the CEL back on. It normally idles fine for a day, week, 2 weeks, whatever, then it seems that once I run the car, you know drive it for about 30 minutes, I usually get the CEL again and its always code 72 or misfire in two. Once that goes on, then I hitting on three. So its not like the car runs on 3 all the time, its hit and miss off and on, but again, it normally comes on after the engine is hot and once its on, is when Im, hitting on three or having super rough idle.

Thats the scoop. Any mechanics in my area interested in some work? I want someone whom knows what there doing and can fix this. Its this or the Tustin dealership is going to take a look. Im just not sure about this low compression thing. I mean, if its low, wouldnt I notice it in my power? I feel power from 0-06 no problem and no power loss though the rpm's either? Ive got power, Ive got good clean rev's all the way up to 8k, its only the idle that sucks. And CEL is normally on after I run it.


Let me ask this. The mechanic did my vavle job in two hours. Engine came in warm and I didnt have time. Could it be that he did them warm (heat expands), set the vavles and perhaps now there a tad tight? I ask this, because my head seems much hotter. And my thinking is, I didnt have this low compression issue or hot head when they did the vavle adjustment, so why now? And there pointing towards a bent vavle or the seat isnt seating correctly. Well, could that be because the vavles were possiable set to tight, drove it for about 3 weeks till I noticed CEL again. Can it be that he got them to tight, now there burnt, hence my issue with compression now? Im fishing here, so please understand Im not saying thats what happened, but could it be that? I guess when I go to Tustin acura, they will tell me whats up. There really good, but always busy and thats the reason I went to the other one the day I needed the CEL orginally checked. I'll just be pissed if they tell me my vavles are done or that there totally off. Also, the mechanic whom did my vavles said, 2 where loose and one was tight. And why is my head so much hotter now?

Thanks to you all
Don aka Ramman949

2000 Integra GSR
Black on Black Leather
16" 6 star DPM Wheels (Japan)
Ground Controll...Lol, I know I know
Warm air intake w/K&N
Wires
ACT cluth, but not installed yet... stock still good

 

most gsr's pull somewhere in the 220-240 psi during compression tests. on another note, compression tests are supposed to confirm different compression ratings from cylinder to cylinder. ideally, they are within 5 psi of each other. i'm sure you already know, but yeah, your readings are way off from what they should be, especially that cylinder 2 of yours. i dont remember reading it, but is your car under extended warranty?

 

nope, its passed it. 50k was my limit.

 

:angry: God I hate mechanics. Everytime they pull this BS!

 

Well then whats your suggestion?