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General Forums => The Mess Hall => Topic started by: mikeb on January 29, 2007, 10:06:41 PM

Title: 2.5L Compression PSI
Post by: mikeb on January 29, 2007, 10:06:41 PM

First off thanks for all the great information. Im on my second jeep and you all have been big helps for my projects.

I looked up the compression for the 97 2.5L and the range was between 120-150.  Thats a big difference! my 97 jeep has a compression reading of 120 accross all cylinders. Is this acceptable?  Truth be told the jeep has about 150,000 miles on it. Is it time for a re-ringing? The good thing is that I am burning no oil. The jeep just feels slugish compared to my 91 2.5L. Both are running 31's.  I thought the tj engine was a little better because of the injectors and other tweeks. Am I wrong?  To top all of this off it only gets about 13MPG on a good day. (new O2 installed too)

I rebuilt my 91 2.5L wrangers engine and sold it before I could check the compression. I couldnt tell to much of a difference.  How well do the High performance and or total seal rings work. Have any of you used them and felt any real performance gains?

Any help would be greatly appreciated.

MikeB

Title: 2.5L Compression PSI
Post by: Jeffy on January 30, 2007, 12:19:13 PM

what's the difference between the cylinders?  Are they all 120?  Max variation should be no more then 30psi.

Title: 2.5L Compression PSI
Post by: mikeb on January 30, 2007, 12:26:10 PM

yep all the cylinders are reading about 120. The second from the front has the highest at almost 130. But other than that they are the same. I even checked them with two gauges. Same readings.

Thanks for the responce, keep them comming.


MikeB

Title: 2.5L Compression PSI
Post by: mikeb on January 31, 2007, 08:20:15 AM

Anyone....   Anyone else....?

Title: 2.5L Compression PSI
Post by: Jeffy on January 31, 2007, 11:48:19 AM

Well, they are within spec.

Title: 2.5L Compression PSI
Post by: mikeb on January 31, 2007, 11:58:46 AM

Okay, I really appreciate your replies!  It sounds like a fine for now vertict.

Thanks

Mikeb

Title: 2.5L Compression PSI
Post by: Jeffy on January 31, 2007, 12:04:32 PM

The biggest concern is usually having one or more cylinders off by a lot.

Keep in mind that with 31's and stock gearing, it might feel sluggish compared to stock.  Although, your speedometer will read slow and the higher seating position will make it look like you are going slower then compared to if you were driving a car at the same speeds.

You could correct the gearing for the tires but it's on the expensive side, and if you decide to go larger, then you'll want to regear again.