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Diagnosing coolant in cylinder


Active Member
June 15, 2017
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City, State
Year, Model & Trim Level
1994, Navajo
1986, Xr4ti
Hey all I've had an ongoing issue with my 1994 Navajo. Once it got to operating temp the gauge would bounce back and fourth from 1/4 to 3/4 and after a while I could smell burning coolant. I flushed the system three times, changed my thermostat, radiator, radiator cap, and temp sensor but problem remained the same. It always ran great with the only drive-ability issue being that it would have a rough idle on hot start I just assumed I needed to clean throttle body because it would go back to normal once I started driving. so I brought to mechanic for diagnosis. I believe he only conducted pressure test on cooling system because it ran great. He told me the water pump was leaking(really started after test) fan clutch was on its way out. I changed them myself but nothing changed. I was beginning to think that my gauge was faulty but I knew about some weaknesses in heads. I forgot to mention that the previous owner had the head gaskets changed and heads resurfaced which was 6 years ago and only about 10000 miles ago because it wasn't driven a lot which makes me wonder. In the last couple weeks maybe 1 out of every 20 starts I noticed a little white smoke on startups for only a second, it was more noticeable when it sat I think. I have had no visible coolant in oil but have had brown sludge in reservoir as well as a gasoline odor which should be gone considering the flushes I've done and the radiator change. The last drive I took it on it had bad misfire my entire drive (about 30 min in traffic) I ran out of gas as I was getting to school my gauge doesn't work and I knew I was pushing the miles I normally put on a tank. I got gas in it less than 20 minutes later and it fired right up but was bellowing white smoke. I parked it and called a tow truck and didn't start it back up till I pulled it up on the bed and off and it fired right up each time. The next day I tried to start it but it felt like the starter didn't have the power to crank it so I didn't try again. Upon inspection I could see coolant seeping around rear driver side spark plug. I pulled it and coolant drained out I immediately began tearing it apart to look further and assumed my heads were cracked and I could do a compression test by hand I used some penetrating grease on various bolts and I am not sure if I got it on the other plug but the plug next to it seemed wet as well but not on the same scale. I removed all the plugs and engine rotates by hand but I compression test by hand was impossible I could feel compression but I couldn't get a fast enough rotation on any cylinder to get gauge to read compression. I could hear a slight hissing sound which I read could just be cold rings. When I started taking the upper intake off I noticed some pooling of a black oily water substance which I know is not normal but don't know the cause. The upper intake had a nice new looking felpro gasket and I also got the valve covers off as well as taking off some possibly unnecessary junk to make my life easier. So my main questions are:

Is it odd that I am still not getting any visible coolant in oil even though on my last drive I lost a large amount of water? There was a very small amount of coolant on tow truck bed but it was dark so I could not find external leak.

Is this definitely a head/head gasket issue or is it possible the lower intake could be leaking into cylinder? My last truck had a GM 4.3 and I almost did heads but it was just the factory trash lower intake.

What are the possibilities that I have done major damage to the rods or other internal engine components and how would I know?

My first thought was buy new heads. Morana is very expensive, then there are king heads and slightly cheaper ProMaxx(Alabama?) should I just bite the bullet and order these before I get it torn down? Loaded or bare heads? I don't want to track down all the parts but also don't want to put trash heads on it.

Is there any other maintenance items I should try to replace while I'm in here without breaking the bank?

It is a 94 Navajo 5 speed 4WD with ~165k I bought it from the original owners son still in his parents name with all the maintenance records since 95 so I really wasn't expecting these issues. Sorry for the length and unnecessary details. Any advise could GREATLY appreciated.

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Maybe it did have a bad waterpump or some kind of not a big deal leak in the first place,
Then it caused your engine to get too hot and it busted your heads or head gasket?

You can borrow compression testers from O'Reileys or Autozone for free. All you have to do is give them a deposit which is returned as long as you bring the tool back. A proper compression test would gold.

I used to have a Dodge 4.7 V8 with very similar symptoms to your Navajo and it had a bad head gasket. I even patched it at one time for about 10,000 miles with some Bars head gasket stop leak stuff which I was amazed that it worked.

Whatever you do, do not use a head gasket stop leak. That stuff is super nasty to your coolant system.

Before doing anything, I would re-torque the head bolts. The fact that it wasn't driven much after the head gasket change could mean the head bolts have loosened up just enough to allow coolant to seep past the gasket. Or the proper torque procedure was not used. Or it was not tightened all the way down in the first place.

Keep it simple before throwing money at it.

Yes MrQ is right. I'm not suggesting using stop leak hahaha. It did make my coolant discussing. But that dodge had EVERYTHING wrong with it towards the end of it's life and it was either stop leak or the junk yard.
Definitely should have specified NOT to use it for your application since you want to keep your truck long term.

Thanks for the suggestion on re-torquing I never considered that. I would not use the stop leak on this vehicle. I have done three or four flushes to get my system clean so that would be counter productive. What has confused me is how well it was running with very consistent symptoms. I have read that the passenger side head is usually the problem and that is not my case. With these particular motors do the head issues usually not cause driveability issues or oil and coolant mixing? I guess it wouldn't hurt to tighten the heads and turn it over with the starter with the intake off and get the compression on each cylinder before I spend a lot of money.

After checking the torque on the heads I decided to take them off. I was very fortunate the exhaust bolts came out easily with no breaking. You can clearly see the coolant in the cylinder also note I added oil through the spark plug hole to perform the compression test. I tried to take detailed photos of everything and can take more. You can see damage to the head gasket around the problematic cylinder the metal is still in tact but the gasket material is missing between the water jacket and cylinder wall. The middle cylinder has some similar damage around the water jacket but it appears to be completely clogged. I am assuming some kind of stop leak was used in the past. I am going to drop the heads off at a machine shop tomorrow to get checked out tomorrow. Is it recommended to buy new push rods? Clean lifters? What kind of stuff is recommended to freshen up the top end while I'm in here?














if the heads check out make sure you get a flat to check the block surface look into bores for irregularities

^ What he said. Either somebody did a piss poor job of cleaning the heads before installing the gaskets or you have warped heads.

Torque to yield bolts require replacement when you remove them .

Whoever came up with torque to yield bolts is a freaking moron.

What are the indications of warped heads? Unfortunately I didn't get around to dropping the heads off this morning before work. What should I be looking for when inspecting my rocker arms and push rods or should I just plan on replacing the pushrods? I didn't notice pitting on them but it seemed like there could be some burnt oil on them. I am also curious about the correct procedure for cleaning lifters.

Visually, you probably wouldn't be able to tell if the heads were warped. It doesn't take much though.

What I meant was are the heads being dirty a sign of being warped?

No sir , dirty has no bearing on if they are warped
You can check them with a carpenter's square if you have one , and a set of feeler gauges .

So the machine shop said the head needs more than resurfacing. It needs some machining and some valves I believe. Which will total about $500 and can be done in two days. So now my options are buy new loaded heads from King or promaxx for $150-200 more or get my head's fixed. I've heard some of the aftermarket heads some extra metal in common problem areas. But this is my daily driver so I need to make a decision today. Any opinions?

Go with the loaded, IMHO.

Does anyone have experience with either manufacturers promaxx or king? Promaxx was formerly Alabama cylinder heads apparently.

Sorry I missed this thread but I bought King and they were really nice pieces. Visually beefier

Sorry I missed this thread but I bought King and they were really nice pieces. Visually beefier
Thanks I actually went with king as well. I gave them a call and they were running a deal where they included gaskets and bolts but I had already purchased and the guy still gave me a discount. The heads were really nice but I did get them checked out by the local machine shop they said they looked good but one wasn't getting a perfect seal on the intake side and that it would probably be fine. I let them do there thing to fix it. It was peace of mind, it was cheap and they looked at my old heads for free. I'm sure they would have been fine really but I didn't want to have any issues.
Im probably around 5k on them and they have been great.

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