Oil leaking from head gasket?

huie83 · Jun 13, 2009

Hey Guys,

97 jeep Cherokee, 4.0 with 159K miles.

Is is possible to have oil leaking from the head gasket? Last month I replaced the valve cover gasket because it was leaking pretty bad. After the gasket replacement I cleaned the engine really good.

Today while tinkering, I noticed oil on the side of the block again. Looks like it is on both sides near the middle of the block. Checked the valve cover gasket,it looked good, the head was dry. Looks like it is seeping from between the block and head, is this possible or is it residual oil running down from somewhere? Has anyone ever had this happen?

Nothing in the oil or in the coolant... Runs rough for the 1st 30 seconds on start up. Just gave it a full tune up; rotor, car, plugs, wires ect...

I have a 600+ mile trip planned next month, will it be ok? It doesn't even leak enough to leave oil spots while parked for days on end.

Saudade · Jun 13, 2009

There are oil passages that allow oil from the valve train to drain back down into the sump. I suppose it's possible. I'd give it another good scrubbing and check it again.

Take a closer look towards the front of the engine. Oil could be leaking from other places and running along the seam, then pool up and drip.

Not sure about the driver side, but there's plenty of other places on the pass side for oil to sprout out. Check the distributor mount, oil pressure sender and oil filter adapter. Oil can wick up the side of the block too.

ceb0217 · Jun 13, 2009

ya my 90 does the same thing make sure that the PCV is clean and that you have good vacum to the pcv.

5-90 · Jun 13, 2009

It would be possible on the passenger side, but not really on the driver's side.

The oil drains back from the top of the cylinder head down the lifter/pushrod gallery on the passenger side, but it's not a pressure seal.

If you're getting oil down the driver's side of the engine, scrub it clean and recheck - you'll likely find that the oil is coming from under the valve cover, and not under the cylinder head.

It is, in fact, fairly rare for the head gasket to leak oil on the drainback side as well - make sure it's not also coming from the valve cover (not doubting you, just sayin'. I've seen it happen plenty of times.)

If it is in fact the cylinder head gasket that is leaking on the passenger side, the gasket can be changed in an after-noon - just let the engine sit for 24 hours before you start the job to prevent warping the head due to relieved thermal stresses (a cylinder head should only be removed and installed when the engine is dead cold.

If you're getting engine oil leaking from the cylinder head gasket on the driver's side of the engine block, something is wrong - and you're going to have to work to find out what. As I mentioned before, there's no oil drainback down that side of the engine. No oil transport means that it simply should not be leaking from there - and if it is, it's coming from somewhere it's not supposed to be in the first place. There's no reason at all for oil to leak anywhere from that side of the engine (where the manifolds are, for our RHD owners,) except from either the valve cover or the oil sump gaskets.

XJ-PRO · Jun 15, 2009

This is exactly what is happening to my 01. The oil it's just coming out of the passenger side of the engine in between the cylinder head and the block, and it's been getting worse and worse.
I have owned this XJ from 2-1/2 years now and I have never had any overheating issues, it just works great. Anytime now I'll replace the gasket and just wanted to ask if it's necessary or a good idea to send the head to the machine shop to have them check it, just to be on the safe side??

Thanks.-

XJ-PRO
Bone stock 01 limited with rear ZJ disc brakes and working parking brakes.

5-90 said:
It would be possible on the passenger side, but not really on the driver's side.

The oil drains back from the top of the cylinder head down the lifter/pushrod gallery on the passenger side, but it's not a pressure seal.

If you're getting oil down the driver's side of the engine, scrub it clean and recheck - you'll likely find that the oil is coming from under the valve cover, and not under the cylinder head.

It is, in fact, fairly rare for the head gasket to leak oil on the drainback side as well - make sure it's not also coming from the valve cover (not doubting you, just sayin'. I've seen it happen plenty of times.)

If it is in fact the cylinder head gasket that is leaking on the passenger side, the gasket can be changed in an after-noon - just let the engine sit for 24 hours before you start the job to prevent warping the head due to relieved thermal stresses (a cylinder head should only be removed and installed when the engine is dead cold.

If you're getting engine oil leaking from the cylinder head gasket on the driver's side of the engine block, something is wrong - and you're going to have to work to find out what. As I mentioned before, there's no oil drainback down that side of the engine. No oil transport means that it simply should not be leaking from there - and if it is, it's coming from somewhere it's not supposed to be in the first place. There's no reason at all for oil to leak anywhere from that side of the engine (where the manifolds are, for our RHD owners,) except from either the valve cover or the oil sump gaskets.

5-90 · Jun 15, 2009

XJ-PRO said:
This is exactly what is happening to my 01. The oil it's just coming out of the passenger side of the engine in between the cylinder head and the block, and it's been getting worse and worse.
I have owned this XJ from 2-1/2 years now and I have never had any overheating issues, it just works great. Anytime now I'll replace the gasket and just wanted to ask if it's necessary or a good idea to send the head to the machine shop to have them check it, just to be on the safe side??

Thanks.-

XJ-PRO
Bone stock 01 limited with rear ZJ disc brakes and working parking brakes.

You can check it yourself with a good straightedge (a nice heavy ground one, not a ruler - or a granite surface table or a thick plate of glass) and feeler gages. It's not terribly likely that the head would warp that far away from the combustion seals, but getting it checked isn't a bad idea.

XJ-PRO · Jun 16, 2009

5-90 said:
You can check it yourself with a good straightedge (a nice heavy ground one, not a ruler - or a granite surface table or a thick plate of glass) and feeler gages. It's not terribly likely that the head would warp that far away from the combustion seals, but getting it checked isn't a bad idea.

Thanks buddy, I'll do so just to make sure, it runs like a charm!!!!!!!

Oil leaking from head gasket?

huie83

NAXJA Forum User

Saudade

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ceb0217

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5-90

NAXJA Forum User

XJ-PRO

NAXJA Forum User

5-90

NAXJA Forum User

XJ-PRO

NAXJA Forum User

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