V8 Coolant Leak

[Xylene]

I have a 1998 explorer V8 that is leaking coolant. I replaced the waterpump last night because it appeared to be where the leak was coming from. After replacement I am still leaking and now notice coolant around the timing chain cover gasket (I replaced this 5 years ago) Is there anything above the time chain cover that could also be causing the coolant to show up there. I don't want to tear into it and replace the timing chain gasket to only realize it was something else on top of it like an intake manifold or something. Also could old waterpump bolts cause a leak like this?

Also while I am back in the timing chain area, can I replace the timing chain without pulling the engine by accessing it from the cover? Is this a worthwhile adventure (140K miles) What kind of tools/expertise is needed to accomplish this?

Thanks

 

[masospaghetti]

Do you have 2WD or AWD?

It's harder with AWD, but still doable, to do everything you're wanting to do without pulling the the motor. The front diff restricts access to the oil pan bolts but it can be done. Just know that despite what Felpro or anyone else says, you MUST drop the oil pan slightly to get the timing cover off. The dowel pins won't let go until you do, and you'll end up breaking the cover and having no way to get a new one in place.

Broken water pump bolts are very common, are you sure they are all there? They will cause leaks if they are missing. Also, when you change the pump, you tend to disturb the timing cover seal and it will leak also.

 

[Xylene]

It is the AWD. I did the time chain cover about 5 years ago and still remember the pains I had to go through to get the gasket replaced.

All nine bolts are still there and before I installed them while replacing the waterpump I cleaned them up and coated them with a gasket sealer. (Instructions on the gasket sealer bottle said this was a good idea)

Anyway I don't mind taking it all apart again and replacing the timing chain gasket, but I don't want to be surprised again to find out it was something else above it that was really leaking.

 

[1998Exp]

Unfortunately, coolant leaks from the top right and left corners of the timing cover are common for this engine. That's because the gasket is very narrow in that area. On my third (yes, third) attempt to fix this problem, I used a metal gasket (covered with RTV on both sides) instead of the paper one and it seems to be holding well.
If you've done this job before you know that it's no walk in the park. And yes, it's a fight to slip the timing cover over the dowels with the oil pan in place, but it's possible, because the dowels have a tapered end. Removing one more bolt on each side, past the one that holds the timing cover will give the pan a bit of flexibility. I used the two bolts next to the dowels to pull the cover in place with a lot of lubricant (don't blame me if you end up breaking it this way!)
Once there, I would recommend replacing the timing chain. You will be amazed how tighter the new chain feels. You may need a puller if the top gear is stubborn, but that's about it. And talking about gears, I would replace them along with the chain - cheap insurance.
By the way, I am not sure it's a good idea to coat the water pump bolts with anything slippery -- that may cause them to lose torque, back up and create a leak.
Good luck!

I have a 1998 explorer V8 that is leaking coolant. I replaced the waterpump last night because it appeared to be where the leak was coming from. After replacement I am still leaking and now notice coolant around the timing chain cover gasket (I replaced this 5 years ago) Is there anything above the time chain cover that could also be causing the coolant to show up there. I don't want to tear into it and replace the timing chain gasket to only realize it was something else on top of it like an intake manifold or something. Also could old waterpump bolts cause a leak like this?

Also while I am back in the timing chain area, can I replace the timing chain without pulling the engine by accessing it from the cover? Is this a worthwhile adventure (140K miles) What kind of tools/expertise is needed to accomplish this?

Thanks

 

[Turdle]

On occasion the little elbow hose will develop a small crack which will only spray under high pressure, leaving a tiny puddle on top of the timing cover area.

If you squeeze the hose you might be able to see the crack better

I hope you get lucky and this is the problem.

 

[Xylene]

I have had that luck once before, it had a very tiny pinhole in it. But this time it appears to be coming from the gasket or something right above it.

 

[beach]

I have had that luck once before, it had a very tiny pinhole in it. But this time it appears to be coming from the gasket or something right above it.

T-stat gasket/housing leak?

 

[Xylene]

Here is a strange twist. I bought the new gaskets so I could start work on changing them out, but by the time I got home the leak had stopped. Then this morning the leak was back. So it seems to be affected by a fully heated/hot engine and a cold engine. Any ideas?

 

[Turdle]

Cold engine leak is timing cover gasket.

 

[MAS Tequila]

Here is a strange twist. I bought the new gaskets so I could start work on changing them out, but by the time I got home the leak had stopped. Then this morning the leak was back. So it seems to be affected by a fully heated/hot engine and a cold engine. Any ideas?

Mine did that a couple of years ago.

It turned out to be the t-stat housing.

When it would get hot it would spray out of a crack that you couldn't find when it was cold.

Get the NAPA gasket that has adhesive on one side, it makes it a lot easier to install.

MT

 

[Xylene]

Mine did that a couple of years ago.

It turned out to be the t-stat housing.

When it would get hot it would spray out of a crack that you couldn't find when it was cold.

Get the NAPA gasket that has adhesive on one side, it makes it a lot easier to install.

MT

Thanks, I wish that were the case, but what I am seeing is the opposite. When the engine becomes fully hot the leak goes away, but when the engine is cold/colder it leaks coolant. I have had that same problem with the t-stat housing as well.

 

[Xylene]

I ended up just tearing the whole thing down again and replacing the timing chain cover gasket. Put it all back together and no more leaks (Although my one of my water pump studs broke on me, and I am having a hard time finding a replacement, how long do you think it will take before it begins to leak where that stud is broke. I left it in for now until I can find a replacement.)