Head or rings??

Firefyter_Emt · 08-21-2003, 02:13 PM

Well, I have looked into my rough idle today.. While it is getting pretty tired, it ran good until Tuesday.. Today I just did a compression test and I have 130-135 on #1,2&3 but just 70 on #4. Now the motor has had massive blow by since I have owned it .. Like if I pull the filler cap or PCV tube it looks like a fogger machine!! However, it does not burn any out the tail pipe that you can see (I am sure there is some just from the amount of "re-burn" form the PCV) Although all my plugs look mint, nice and whitish cream color.. Do you think it may just be in the head and I can sneak by with a used head?? The motor is tired (175k) but I am broke with buying a new house and the compression seems fair enough for the mileage.. Plus it is such a freaking simple head to pull off... I don't have access to put compressed air to #4 yet.. But I will try it later. What do ya all think??

The motor suspect is a 2.5L in a 91 Wrangler

MC · 08-21-2003, 02:37 PM

fogging really doesnt mean anything.......all engines fog but some have really tight baffled oil pans and dont as much, if it is really really really bad it could be rings but you would know it would be coming out of the exhaust but if oil is making its way into the pcv tube then yeah I believe it would be the lower oil rings that are shot........been a while since ive had that problem

95steel · 08-21-2003, 02:41 PM

I have a 4.0 HO in my jeep, rebuilt my head for less than 200 including machine work. Most machine shops will clean it up and magnaflux(sp) it and inspect for cracks, resurface it, clean and relapp the valves for cheap. I spent 100 for machine work and about 100 in gaskets, pushrods, valve seals, springs and a case of beer.

Find a machine shop and tell them what is going on with your engine and tell them you want to freshen up the top end. They should be able to give you a quote. If the problem is in the head. You could also just check the salvage yards for another 4 banger with less miles. Found one for my neighbors yj for a couple hundred. Just used the long block and all his old accessories. honestly I think it took less time to swap his engine than pulling the head on mine.

Firefyter_Emt · 08-21-2003, 05:33 PM

Yea.. I gotta dump some oil in the plug hole and see if it comes up at all.. I didn't have time to find a funnel I could use tonight..

I would be going the used head route if it is bad..

08-21-2003, 02:37 PM	#2
MC www.Bulltear.com Join Date: Aug 2003 Member # 21997 Location: Multi axis machined parts, CNC Plasma tables Posts: 4,162	fogging really doesnt mean anything.......all engines fog but some have really tight baffled oil pans and dont as much, if it is really really really bad it could be rings but you would know it would be coming out of the exhaust but if oil is making its way into the pcv tube then yeah I believe it would be the lower oil rings that are shot........been a while since ive had that problem __________________ Bulltear CNC plasma support forum click here We offer Rods ends! Coil-overs! Air shocks! Billet items! QA-1 coils and Rock Ends! Own a full blown Plasma CNC for less, click here

08-21-2003, 02:41 PM	#3
95steel infidel Join Date: Oct 2002 Member # 14509 Location: North West Arkansas Posts: 1,121	I have a 4.0 HO in my jeep, rebuilt my head for less than 200 including machine work. Most machine shops will clean it up and magnaflux(sp) it and inspect for cracks, resurface it, clean and relapp the valves for cheap. I spent 100 for machine work and about 100 in gaskets, pushrods, valve seals, springs and a case of beer. Find a machine shop and tell them what is going on with your engine and tell them you want to freshen up the top end. They should be able to give you a quote. If the problem is in the head. You could also just check the salvage yards for another 4 banger with less miles. Found one for my neighbors yj for a couple hundred. Just used the long block and all his old accessories. honestly I think it took less time to swap his engine than pulling the head on mine. __________________ Click Here For Awesome Metal Fabrication Equipment From BAILEIGH INDUSTRIAL

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08-21-2003, 02:13 PM	#1
Firefyter_Emt Registered User Join Date: Nov 2000 Member # 2192 Location: Connecticut Posts: 832	Head or rings?? Well, I have looked into my rough idle today.. While it is getting pretty tired, it ran good until Tuesday.. Today I just did a compression test and I have 130-135 on #1,2&3 but just 70 on #4. Now the motor has had massive blow by since I have owned it .. Like if I pull the filler cap or PCV tube it looks like a fogger machine!! However, it does not burn any out the tail pipe that you can see (I am sure there is some just from the amount of "re-burn" form the PCV) Although all my plugs look mint, nice and whitish cream color.. Do you think it may just be in the head and I can sneak by with a used head?? The motor is tired (175k) but I am broke with buying a new house and the compression seems fair enough for the mileage.. Plus it is such a freaking simple head to pull off... I don't have access to put compressed air to #4 yet.. But I will try it later. What do ya all think?? The motor suspect is a 2.5L in a 91 Wrangler

08-21-2003, 05:33 PM	#4
Firefyter_Emt Registered User Join Date: Nov 2000 Member # 2192 Location: Connecticut Posts: 832	Yea.. I gotta dump some oil in the plug hole and see if it comes up at all.. I didn't have time to find a funnel I could use tonight.. I would be going the used head route if it is bad..