Coolant leak above valve cover?

I noticed recently that my coolant level was low. After topping it off and driving for about a month I noticed my level was low again. There is some dried coolant spatter around the main hose, as well as around the radiator cap. Inspecting the engine with my buddy, he noticed that there was some wetness on top of the valve cover on the driver side, towards the front, like below the fuel rail. We scraped it with a flathead and low and behold - it is coolant. Anybody experience a coolant leak above the valve cover? What could be leaking up there?

 

I can’t remember, but is there a coolant hose that runs to the TB on those trucks?
Maybe it’s coming from there?

Around the radiator cap might indicate a weak cap.

Around the main hose? Well I’m not sure what one you are talking about?

I’ve seen the cooling fan sling coolant in some odd paces.
Look around there too.

 

Pictures, pictures, pictures, pictures.

Oh and uhm, pictures.

When I had a 'leak' up top, it was from the smallest crack on the plastic expansion tank up top of the radiator.

Replaced the radiator and all was said and done.

Oh by the way, pictures.

 

The exterior of the TB looks clean, no coolant in that area.

This is what the cap and main coolant hose look like:



This is the area where my buddy and I found some liquid coolant after a short drive. It was below the intake plenum pooling on the head:


Tough to get a good photo of the area, but this is where it was if you're looking down from the top:

 

I see signs of coolant all over.
As for the hose, believe it or not, the pinch type clamps seem to be better.
They will retain spring Tension even as the hose heats up, cools, and ages.
My point is, the clamp might be the issue there.

I can’t say as to the Valve Cover. It would probably take further inspection.
A coolant pressure test would be a good start. Just don’t go over the recommended psi.
Usually the psi of the radiator cap is a good max. I try to stay under that pressure just to be safe.

 

Can't comment on the intake manifold, but that tiny bit of splatter by the radiator cap is what I also had. Inspect the radiator once more -



Hopefully someone chimes in on the pooling though.

 

I believe you. The cable clamp is a holdover from the PO, I plan on replacing it with the OE constant tension clamp. This week I'll pull the intake plenums off and see if I can determine where the leak is coming from.

Taking a look at a 5VZ I have on a stand in my garage, it looks like there is a coolant tube running from the water pump out towards the rear of the engine:


Possible source of the leak on my truck? It looks to be about where the leak is coming from. Also, I am long overdue for a timing belt/water pump. Does anyone know if these water pumps weep when they're bad like on old chevy's? @Kwikvette ?

 

I think I see the beginnings of a crack going at an angle upwards and to the right, terminating beyond the overflow hose you disconnected. I replaced the original radiator on my 2001 a few weeks ago for a crack in the plastic VERY close to where yours appears to be failing. Observe my crack....lol

 

When you pull the intake off check your intake valves and maybe clean them, the motor you have with the photos shows the
valves are FILLED with carbon that will make the engine run lean.

Here is your valves and a photo of mine when I had my supercharger off.

 

When i did my TB/WP, the pump was starting to weep, but not noticeable like a Chevy. I had to take the TB cover off in order to see it...

 

yes, that motor I used for the pictures has been sitting for a while in the garage, never been in my truck. I’m not sure about it’s history.

thanks! This is interesting to know. I will start getting into the engine tomorrow and take some pictures of what I see in there.

 

Pulled off the throttle body and intake plenums today. Underneath the lower intake plenum on the driver's side was a significant amount of dried coolant buildup. Gross. I am confident that this is where all my coolant has been mysteriously disappearing to:




As far as the source is concerned? I am still not sure. Below you can see there is some residue where the upper radiator hose meets the engine. Though I'm not sure that's enough to cause the mess that I'm seeing. I'm also trying to get the timing belt cover off so that I can inspect the water pump, but the PO used one of those metal hose clamps on the upper radiator hose so the cover will not fit around it and come off May have to flush it, pull that hose off, and get the timing cover off to see what I'm dealing with.

 

Took a closer look after talking with my buddy again, found one more clue:

See the wetness above the oil filter? Freeze plug. Here’s a closer look at it:


My buddy thinks the freeze plugs may be the source of the leak, but I’m not understanding how the coolant is finding it’s way above the lower intake manifold. Can anybody see how it gets there? Do you guys think the freeze plugs are causing this leak?

 

I think you need to get that engine steam cleaned so you can get a better view of what’s happening

 

Do you have access to a pressure tester?
I would pressure test it and look for leaks now that you have a more room to look.
Leave it under pressure for a little bit, give it time to seep out.

 

I do. That’s a good idea. Just looking and talking it over with my buddy, we think the leak is below the lower intake manifold, most likely a worn out seal on the coolant bypass pipe like I was saying above. It’s apparent that this coolant system was not well taken care of! I can only blame myself for that, I should have flushed it when I bought the truck and replaced the timing belt and water pump when it was due lol

 

Yeah, lots of things can happen and be forgotten about in 24 years.
I’ve only ever replaced 1 freeze plug. It was on a Ford Ranger. Thankfully it was one you could access fairly easy.

As for the intake leaks, well it is 24 years old.

Thanks for the update. Let us know how it turns out.

 

Yeah for sure, thank you for the help man. I’m gonna do the freeze plugs after I pull the manifold. Any thoughts on the rubber kind? I’m thinking they’ll be easier to install than the brass plugs

 

there are worse places to leak than that... search on

Mystery coolant leak found.

 

Never used the rubber style.
Personally, I wouldn’t. And that’s only because I don’t know much about them.
Sometimes you do what you have to do. If you can’t get to the one that’s leaking to drive a new metal one, then the rubber will have to do I guess?