Head Gasket?

[JustinGibson]

Hi all,
My 94 navajo was running rough a couple weeks ago and I have been losing coolant. At one point I saw coolant had dripped on my front axle so I thought it was a hose or lower intake gasket. I took the upper intake off and checked the torque on the lower intake which was tight and tightened the hoses which some were loose.
I put it back together and it ran a little better for a couple days (just a few short trips) before it start running like garbage. Strong fuel smell from the gas, liquid spraying out of exhaust, no power and backfiring here and there.
I assumed it was the head gasket which I replaced myself about two years ago. As I am taking off the plastic intake to do a compression test I see there is a little bit coolant inside of it and around the edge of where the crank case hose attaches to it. The weird thing is I can't see coolant in the oil and the oil levels are normal. When I took the intake off two weeks ago there was some oil in it which did look a little cloudier than normal but I didn't think much of it just thought maybe it got wet or had some humidity in it but this is definitely coolant. The throttle body is dry so it is weird there is coolant apparently coming from the crank case hose?
Any ideas what could be going on?
My fuel pressure test seemed good and I will post my compression test results when I finish.

Thanks

 

[Mbrooks420]

You can have a head gasket leak with none of it getting into the oil. They often leak to the exterior of the motor.

A leak down test might point to a cylinder. None of the spark plugs came out cleaner than the others?

 

[JustinGibson]

You can have a head gasket leak with none of it getting into the oil. They often leak to the exterior of the motor.

A leak down test might point to a cylinder. None of the spark plugs came out cleaner than the others?

Yeah last time it blew it had a break in the gasket between two cylinders and was not visibly getting into the oil but so far it seems there is coolant in the top of the engine and not in the crank case. So far I have pulled the passenger plugs and they all look the same and they are all dry. I also checked the compression the the three cylinders and got 125 psi for all three. I am getting to the other side now.

 

[JustinGibson]

All 6 cylinders are right at 125 psi. The cylinder 4 plug was wet with gas so I guess it was not getting spark. I see oil leaking from the rear of the driver side valve cover but oddly the rear two plugs were very corroded and didn't want to come out.

 

[JustinGibson]

---

---

---

---

 

[JustinGibson]

Is there any other way coolant could make it's way up here?

 

[JustinGibson]

There is bulges around the water jackets so that is one way.

 

[JustinGibson]

The ball of this pushrod is showing way more than the others which is a little concerning since it is the same cylinder with the fouled plug but I got 125psi on that cylinder. Trying to decide if I should pull the heads or change the lower intake gasket and trouble shoot that cylinder.

 

[JustinGibson]

Any input?

 

[A .SCOTT]

Common water leaks. Lower intake, I fixed one on a friend's X.
Timing cover.. mines leaking now. I had coolant dipping on my front axle found it by doing a pressure test
And check the freeze plugs another leak I have.
A pressure tester for the cooling system is a good tool to have. This is how I found my leaks.

 

[JustinGibson]

Common water leaks. Lower intake, I fixed one on a friend's X.
Timing cover.. mines leaking now. I had coolant dipping on my front axle found it by doing a pressure test
And check the freeze plugs another leak I have.
A pressure tester for the cooling system is a good tool to have. This is how I found my leaks.

Thanks man! So I ended up pulling the heads and it seems there was coolant getting in the cylinder. Cylinder 5 was completely clean and 4 seemed like it was on its way. The cylinder 4 plug was also fouled with fuel.
I believe the headbolts were defective as the 2 inner headbolts for cylinder 4 and 5 were not near as difficult to break loose. I used felpro head bolts as they were cheap and I always used there gaskets but as I was looking to purchase the headbolts to redo the job I found alot of bad reviews on them.

 

[cpocraig]

Hi all,
My 94 navajo was running rough a couple weeks ago and I have been losing coolant. At one point I saw coolant had dripped on my front axle so I thought it was a hose or lower intake gasket. I took the upper intake off and checked the torque on the lower intake which was tight and tightened the hoses which some were loose.
I put it back together and it ran a little better for a couple days (just a few short trips) before it start running like garbage. Strong fuel smell from the gas, liquid spraying out of exhaust, no power and backfiring here and there.
I assumed it was the head gasket which I replaced myself about two years ago. As I am taking off the plastic intake to do a compression test I see there is a little bit coolant inside of it and around the edge of where the crank case hose attaches to it. The weird thing is I can't see coolant in the oil and the oil levels are normal. When I took the intake off two weeks ago there was some oil in it which did look a little cloudier than normal but I didr heads magna fluxed n't think much of it just thought maybe it got wet or had some humidity in it but this is definitely coolant. The throttle body is dry so it is weird there is coolant apparently coming from the crank case hose?
Any ideas what could be going on?
My fuel pressure test seemed good and I will post my compression test results when I finish.

D

Do have your heads checked for cracks. I just did my 94 xlt after having the very same problems. While the head gasket on my cracked was blown too it turned out to have started with the cracked head. I ended up rebuilding the engine as there was pre det damage to #3 with was were the cyl head was cracked. I id the cam to a rec cam and replaced push rods and rockers. She runs strong with that rec cam.

 

[JustinGibson]

I'm not sure what a rec cam is but these are fairly new (less than 2 years old) aftermarket cast heads that I had inspected by a machine shop before I installed them which I also did the pushrods at that time. I plan on doing a full engine rebuild in the future with a cam in the future but it's not in the cards atm.
I'm going to do a visual inspection but I appreciate the advice. How do you identify pre detonation damage?

 

[Mbrooks420]

Predetination will often break a plug and then it’ll lunch the cylinder. It can also damage the piston tops, and it’s also tough on the bearings.

 

[cpocraig]

I'm not sure what a rec cam is but these are fairly new (less than 2 years old) aftermarket cast heads that I had inspected by a machine shop before I installed them which I also did the pushrods at that time. I plan on doing a full engine rebuild in the future with a cam in the future but it's not in the cards atm.
I'm going to do a visual inspection but I appreciate the advice. How do you identify pre detonation damage?

A rec cam is a recreation cam. They generally give a 15-20% increase in power. The pre detonation damage usually shows up in the cylinder that the coolant was escaping in. You'll find it in the cylinder walls. The after market heads are the way I went also. I would still have them checked for piece of mind.

 

[Mbrooks420]

Are you referring to an “RV” cam? They typically move the power lower in the RPM range so it’s more useful in a heavy, slow brick of a vehicle.

 

[cpocraig]

Are you referring to an “RV” cam? They typically move the power lower in the RPM range so it’s more useful in a heavy, slow brick of a vehicle.

That's a rec cam, Recreational Vehicle.

 

[JustinGibson]

Do have your heads checked for cracks. I just did my 94 xlt after having the very same problems. While the head gasket on my cracked was blown too it turned out to have started with the cracked head. I ended up rebuilding the engine as there was pre det damage to #3 with was were the cyl head was cracked. I id the cam to a rec cam and replaced push rods and rockers. She runs strong with that rec cam.

Thanks I'm not going to get them inspected at this time but I am hoping to do a full rebuild in the next year or so and get headwork, cam etc. What cam did you end up going with? All my research has been around the comp 410 and 422.

Predetination will often break a plug and then it’ll lunch the cylinder. It can also damage the piston tops, and it’s also tough on the bearings.

I did not have this happen thankfully! Thanks for the information.

I am putting it back together now and will hopefully have an update by tomorrow.

 

[Mbrooks420]

That's a rec cam, Recreational Vehicle.

I know what RV stands for, I’ve just never heard them referred to as recreation cams.