low compression

steelhorse · **Joined:** Sun Sep 04, 2011 7:24 pm **Posts:** 16

anyone tell me what the compression should be . 2006 died and won't start replace timing belt,tensioners,water pump,exhaust cam,crank and cam sensors,rockers looked fine,did a compression test,3 of the cyl. had 200 psi ,one cyl had 100 psi .. anyone have any idea

jrsavoie · **Posted:** Sat Jun 29, 2013 6:54 am

steelhorse wrote:

anyone tell me what the compression should be . 2006 died and won't start replace timing belt,tensioners,water pump,exhaust cam,crank and cam sensors,rockers looked fine,did a compression test,3 of the cyl. had 200 psi ,one cyl had 100 psi .. anyone have any idea

X2

flash7210 · **Posted:** Sat Jun 29, 2013 7:38 am

Yes, that compression seems low.
How are you testing compression?

What caused the engine to die?
Why did you only replace the exhaust can and not the rockers?
The two work together. if there is damage to one, the is probably damage to the other.

Hexus · **Posted:** Sat Jun 29, 2013 9:02 am

flash7210 wrote:

Why did you only replace the exhaust can and not the rockers?
The two work together. if there is damage to one, THERE IS DEFINITELY damage to the other.

Fixed.

jrsavoie · **Posted:** Sat Jun 29, 2013 9:24 am

The question still is "anyone tell me what the compression should be?"

What do you need in addition to as= diesel compression tester to test the compression?

I'm not terribly familiar with these engines yet.

Do you test compression through the injector holes as was posted someplace or through the glow plug holes?

Thanks

flash7210 · **Posted:** Sat Jun 29, 2013 12:06 pm

Compression should be about 200 or greater.

Best way to test is through the injector hole.

SargeIndustries · **Posted:** Sat Jun 29, 2013 12:42 pm

15 to 20 times the the compression ratio(17.5) should give and estimate of psi. Mine was misfiring on #2 cylinder from lack of compression. It was the head gasket leaking, as the coolant light would come on from time to time from cylinder pressure displacing coolant out of the radiator cap when driven agressively. Just finished replacing head gasket and ARP stud kit. No more coolant light coming on...

LMWatBullRun · **Posted:** Sat Jun 29, 2013 2:11 pm

Sarge, did you notice any of the studs that took more turning to get the requisite torque?

jrsavoie · **Posted:** Sat Jun 29, 2013 5:04 pm

flash7210 wrote:

Compression should be about 200 or greater.

Best way to test is through the injector hole.

Where do you buy an adapter for the injector hole?

Does anybody have a link or recommendation?

SargeIndustries · **Posted:** Sat Jun 29, 2013 8:09 pm

Are you talking about when I removed the old ones? All the old head bolts seemed to require the same amount of force to remove. Others have witnessed mushrooming of the bolt seat. I did not notice any of this on mine. I could definitely see where the head gasket was not sealing on #1 and #2. The new ARP studs were very consistent when torqueing. I went in three stages to bring the studs in the center of the head to 120 and the studs down the sides to 110. They rotated the same in between each stage.

steelhorse · **Joined:** Sun Sep 04, 2011 7:24 pm **Posts:** 16

the reason the exh.cam was replaced the shop i had it at said the cps was not picking up a signal.the cam is on him,it did not fix the problem,the dealership did the compression thest,3 of the cyl. were 200 psi,1 of them was 100 psi,the dealership said the engine was toast,i was driving when it just quit running,plenty of power,not smoking or missfiring

DOC4444 · **Posted:** Fri Jul 05, 2013 10:11 am

You need to do a leakdown test to see where it is leaking (i.e. int valve, ex valve and/or rings).

Let's say a crushed lifter is keeping a valve from fully closing. Continuing to drive with a leaking valve will cause it to burn (assuming that cylinder is firing).

DOC

steelhorse · **Joined:** Sun Sep 04, 2011 7:24 pm **Posts:** 16

does anyone know of someone who know anything about 2.8 jeep in nepa?

Valve Stem · **Posted:** Fri Jul 05, 2013 9:41 pm

Like allentown? like hazleton? like scranton?....I'm down towards Reading

steelhorse · **Joined:** Sun Sep 04, 2011 7:24 pm **Posts:** 16

yes any of those areas,Reading is fine

Valve Stem · **Posted:** Wed Jul 17, 2013 10:54 am

You get your CRD running?

MRausch82 · **Posted:** Wed Jul 17, 2013 3:36 pm

I'll look up the compression specs when I get home. You likely have a bad hg or rockers if it all of a sudden is running rough... I am in n. central PA.

low compression

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