Check out these compression test results

RYC CUKR

Founding Member
May 19, 2002
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1
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Orlando
Okay,

So I have been having some temperature rise issues of late and figured I would do a compression check to try to pinpoint things. I did the test with the throttle blade propped open, coil and injectors disconnected and the engine fairly warm. Probably a little lower than operating temp since I got tired of burning my hands on the headers.

cylinder PSI
1 160
2 175
3 165
4 175
5 160
6 170
7 165
8 160

This is my 93 GT AOD. Has about 160k on the odometer. Just put in a TFS stage 1 cam, trackheat intake, 130 amp alternator and taurus electric fan. The rest of the mods are in my sig.

Here is what the temp has been doing.
At idle it will climb even with the fan on high. usually if I get moving it will come right back down while the car is moving. Today it was just jumping around all over the place. the highest it got was about 230 then it would go down to 200 and then back up to 230 then down to 180 and so on. It has a 180 degree t stat and a 1 year old griffin 2 core aluminum radiator. So this is a little perplexing to me. I am thinking about getting a new t stat and seeing if that helps the problems.
 
That is funky. How fast does it take to fluctuate a given amount (in other words, is it possible for the gauge readings to be possible, or do you think it is a gauge issue)?

If the fan is not helping anymore, I like the stat idea. The fan cant do anything if the stat is sticking closed. If you decide to do the stat, I recommend a Mr Gasket stat (180 is my temp of choice, and that should work for ya down in Fl.).

Good luck.
 
I hope its not a guage issue its new and the damn things aren't cheap.

It fluctuates pretty quickly sometimes. Up from 200 to 230 in about 30 seconds and then back down. One other thing that I noticed it doing was on warm up. The temp gauge would climb up to around 230-240 as it was first warming up and then it would drop down to 180. I am gonna get a Mr Gasket 180 and a new griffin radiator cap from summit and see where that leads me.

Hissin,
How do the compression #s look to you. I thought they were pretty good for a 13 year old car with 160k on the clock. I am contemplating a little nitrous since I only drive the car on the weekends and at the track.
 
I'm thinking there's a possibility of a few little air pockets in your system. Not a lot, but enough to cause it to fluctuate. It it possible that the fan isn't up to the task of keeping it cool? I thought using the Taurus fan was pretty common when going over to an electric fan on a Fox, so this one is definitely odd...
 
The fan is pulling quite a bit of air. On high I can hear it sitting at stop lights. Definetely pulls more air than the original clutch fan did.

I backflushed the system over the weekend just to make sure there wasn't any crap in it. As soon as I get the new T stat and cap I am gonna fill it up and see how it goes. It could be possible that it had some trapped air pockets. I thought that I had burped the system pretty good when I put the new cam and intake on.
 
RYC CUKR said:
Hissin,
How do the compression #s look to you. I thought they were pretty good for a 13 year old car with 160k on the clock.
I agree with Matt - those numbers look awesome for a mill with so many miles.

And your plan for the cap and stat sound good. The thing with air is that if it was in there and was trapped behind an unbalanced stat, the air can knock the stat out of calibration.

Good luck.
 
Well I put the new Mr Gasket 180 stat in and a new radiator cap, refilled the system, burped it and all seems to be well. With the A/C on it is running right at 180 with the fan on low. We'll see how well it does once the temp goes back up down here but everything seems good. Thanks for all the input guys