Going to track, should I worry?

[97gsxturbo97]

Ive spent the last few days preparing my car for the track. I have basically checked everything on the car to make sure everything is good to go. All the fluids are good, no shaft play in the turbo. Suspension is tight etc. I did a compression test for the hell of it and kinda got worried. Let me start off by saying this compression test took me three hours. I rented the tool from autozone. Cylinder one was 157 then cylinder 2 was 90, then cyl 3 was 125 then cyl 5 was 110. I did it again and cyl 1 changed to 125, cyl 2 125, cyl 3 90, cyl 4 105. Every time I did it it changed so I went and got a new tester. Cyl one is now 160, cyl 2 145, cyl 3 160 and cyl 4 160. That was also after doing each one several times I finally started getting those numbers. The engine was hot and the throttle was to the floor. So either I got an inaccurate reading or cyl 2 is actually 145 psi. Should I be worried about taking this car to the track? That particular plug on cyl 2 with 145 psi did have some oil on the threads of the plug when I took it out. Not alot tho. I also notice that the car misses every now and then when Idling but it isnt enough to really cause concern. Every now and then you can hear that little pop or see the engine shake a little. All my chevys did that tho. I figured it has three inch exhaust and no cat so Im going to hear things. Thanks for you help.

 

[crimsondragon]

I know my engine is not in the greatest shape but I still launched it at WOT at stoplights just to feel how great it is. No prepping either. You're fine. You do want to get that checked out though. Leak down test is in order.

 

[pj91gsx]

stock is 180 for 2g. just keep that in mind. I would check the cam timing and look at the igntion timing to make sure your car is at the top of its game.

 

[chris9149]

Cylinder one was 157 then cylinder 2 was 90, then cyl 3 was 125 then cyl 5 was 110.

I would be worried that you have a 5th cylinder!!!

For real though. You should always, in my opinion, be a little worried before you go to the track. It is hard on your car (I guess really depending on how you drive it on the street) and crap is more likely to break. Just be prepared in case you do run into trouble. That one cylinder seems a little low, and the others are all fine. You might want to do the leakdown test and see what you find.

 

[awd6boltsi]

That particular plug on cyl 2 with 145 psi did have some oil on the threads of the plug when I took it out. Not alot tho.

This could be caused from a bad o-ring gasket on your valve cover... it could be leaking and allowing oil down in the spark plug well.

 

[hubz91talontsi]

Always prepare for the worst and hope for the best..

 

[97gsxturbo97]

Well Im going to buy a real compression tester and check it again. I have had problems with the autozone ones that you rent before. The car had ngkbpr7es plugs in them and it was only running 12 psi so it is possible that one of the valves is sticking do to carbon buildup. The guy I bought it from said the plugs dont seem to last more than 12,000 miles and said it must be normal for a turbo engine. I threw in NGKBPR6ES and the car rips now. I will check it again and see what I find.

 

[banishedmunk]

the way i look at it if you are worried then you will never know the full potential of your car. until you start to go really fast then if your not worried then you need to stop racing.

 

[SpiralOut]

I just went to the track for the first time yesterday. My car has 155k i drive it over 100 miles a day, I have ABS plastic tubing as intercooler piping. And i did ten runs without a problem. My best time was 16.55@92. (damnFWD) But i got my reaction time down to .023!!!

 

[97gsxturbo97]

The only thing Im worried about is doing damage to the #2 cylinder. Its only 15 psi difference and I guess it could be worse. I just bought this car and it pulls so strong so im kinda of baffled. Im honestly thinking too much carbon buildup on the exhaust valve due to too cold of a plug being gapped at .035.

 

[SpiralOut]

Seafoam FTW!!!!!

 

[97gsxturbo97]

yes seafoam. My only concern is damage to the turbo? I think Im gonna try some chevron techron first. If no luck then seafoam it is.

 

[MaxGdsm]

i second awd6boltsi, you prob have bad Oring seal on valve cover gasket causing the oil buildup on your spark plug threads.
My car was actually working fine, i brought into my shop, was working on mounting a new hood and then went to start the car and it was missing badly.
I pulled the plugs and one was pretty covered in oil, i kinda freaked but then realized it was pretty fresh and there was oil in the recess for the spark plug, so it was coming down from the top. pulled the cover found two Orings were cracked and replaced them all and she started right up and purred like a kitten. No more miss fire. So eventually youl want to replace those, the valve cover seal kit costs like 30$ and takes all of 30 minutes to do. Just clean everything well, getting the gasket seal off the old valve cover lip and reseal her up.

Other wise youll go to start your car one day and itll only be running on 2-3 cyl.

As for the track, good job checking nuts and bolts. Youll prob be fine, just be sure to monitor fluid levels and temps if possible between runs. Also it isnt a bad idea to have a connection to someone who can get a tow just in case. Ive had several friends go to a track and need a tow home.

Good luck and have fun.

 

[viprez586]

A compression test should be performed as follows:
1) Engine at operating temperature.
2) Battery charger being used.
3) Throttle plate wide open.
4) All spark plugs removed.
5) Cranking engine over 5-8 revolutions or until gauge stabilizes

Rule of thumb is that there should not be more than a 10% difference between cylinders. So 10% of 160psi = 16psi. So close but should be fine.

To determine where it's leaking down you should perform a Cylinder Leak Down Test.
Again bring your engine to operating temperature.
Bring test cylinder to TDC.
Pressurize the cylinder or cylinders in question to 100psi.
Watch and listen for leak down.
Areas of concern:
Howl or puffs from Exhaust tailpipe = Leaking exhaust valve.
Howl or noise from Throttle body(Open Throttle body plate) = Leaking intake valve.
Bubbles or noise from oil cap/dipstick = blow-by.. Rings, PCV valve, etc.
Bubbles in coolant or overflow, adjacent cylinder = blown headgasket, cracked water jacket.

Typically a cylinder that shows poor compression but little to no leak down indicates a worn cam lobe, collapsed lifter, broken valve spring, etc.

If all cylinders have low compression and little to no leak down, this may indicate incorrect timing or your piston is not at TDC. In most cases if your piston is not at TDC it will shoot the piston back down(watch out for flying ratchets or wrenches!).

I think I covered everything but maybe someone else will have more to add. IMHO those compression #s are fine. It's when you get over 20% variation or low compression then you know something is wrong.

 

[PieEyedPiper]

The only thing Im worried about is doing damage to the #2 cylinder. Its only 15 psi difference and I guess it could be worse. I just bought this car and it pulls so strong so im kinda of baffled. Im honestly thinking too much carbon buildup on the exhaust valve due to too cold of a plug being gapped at .035.

.035?! why?

Your car would probably appreciate .028

 

[knochgoon24]

A run at the track may do your car some good. The higher temps may burn off some of the carbon.

 

[banishedmunk]

seafoam has good and bad effects, yes it cleans the hell out of your engine,but in a high mileage motor the stuff that the seafoam cleans out may be what is allowing your compression to stay where it is. Whn that stuff is gone so is the compression.I would try some fuel injector cleaner with a half tank of fuel and do that with the next tank also. That should take care of all the carbon built up on the valves.