Engine/Transmission (1994 - 1998) Coolant leak - thermostat or HG?

[sarchib]

I have a '97 12 valve with 277k on the clock. Noticed this minor (looking) leak that only happens when I go on longer highway drives. The truck never drips anything on the ground, so it's as if it's sprayed out in small quantities when the truck is at operating temperature for a while. Hoping very much that it isn't the head gasket, but I know that's a common issue on these. Any ideas?

 

[CRodi]

It's difficult to tell from the picture, but are those 2 coolant pipes rubbing against each other?

If that's were the leak is coming from, it's a very minor issue.

If it's coming from between exhaust manifold and head, then it looks to be far more serious.

Hopefully, the more experienced and knowledgeable members will chime in soon.

 

[sarchib]

No those pipes aren't touching. I can see how the picture makes it look like they are though.

 

[CRodi]

The only other thing I can suggest is to pressure test the cooling system.

 

[mwilson]

What is the condition of the little hose I circled?? That looks like it would spray at just about the right angle....

 

[savage54]

What is the condition of the little hose I circled?? That looks like it would spray at just about the right angle....


View attachment 99274

I had that hose leak the other way ,in to the fan. I thought it was the radiator. It would only leak when the pressure built up.

 

[sarchib]

It appears to be in good shape... here are some more close up photos

 

[mwilson]

Could be the thermostat housing gasket, it almost appears to be pooling in the low spot directly behind it and then blowing back onto the manifold and stuff. Probably when the fan speeds up....

 

[JR]

Hoping very much that it isn't the head gasket, but I know that's a common issue on these. Any ideas?

I definitely would not agree that it is a known issue on these near bullet proof boat anchor motors. I've owned 2 higher mileage 2nd gens that routinely saw 30+ lbs of boost on near 20 year old headgasket and studs and both are still running strong. In stock or near stock form they are as reliable as anything I've ever seen. Lots of examples in ag and construction equipment with well over 10,000 hard hours...the big variable being proper maintenance. Your engine is proof positive IF it is original, not many engines will last 20 years under boost for close to 300k miles on original head gasket...I'd say that's pretty reputable. At least it is in my book.

 

[BigPapa]

I agree with JR. Mine has just north of 500K with the original head bolts and never had the head off. It sees 30+ boost fairly regularly now and for a couple of years it was seeing 45+ while I was running a different turbo.

 

[mwilson]

Is your coolant mix a 50/50 ratio?
That residue looks way too green.

 

[DavidC]

I definitely would not agree that it is a known issue on these near bullet proof boat anchor motors. I've owned 2 higher mileage 2nd gens that routinely saw 30+ lbs of boost on near 20 year old headgasket and studs and both are still running strong. In stock or near stock form they are as reliable as anything I've ever seen. Lots of examples in ag and construction equipment with well over 10,000 hard hours...the big variable being proper maintenance. Your engine is proof positive IF it is original, not many engines will last 20 years under boost for close to 300k miles on original head gasket...I'd say that's pretty reputable. At least it is in my book.

Technicalities,technicalities :-laf.

Dave

 

[NIsaacs]

Could be the thermostat housing gasket, it almost appears to be pooling in the low spot directly behind it and then blowing back onto the manifold and stuff. Probably when the fan speeds up....

I agree, I think that is where the leak is. Since the cost is minimal I would change it and see. You might be due for a new thermostat anyway. Here is a picture and link of the seal.

http://www.oreillyauto.com/site/c/detail/MAE0/C31421/01378.oap?year=1996&make=Dodge&model=Ram%2B2500&vi=1095869&ck=Search_C2070_1095869_4784&pt=C2070&ppt=C0331


Be careful if you use a local parts house, sometimes they will try to sell you this gasket and seal. It is for an application without the lifting eye.

Nick

 

[sarchib]

Is your coolant mix a 50/50 ratio?
That residue looks way too green.

I agree, I think that is where the leak is. Since the cost is minimal I would change it and see. You might be due for a new thermostat anyway. Here is a picture and link of the seal.

View attachment 99282

http://www.oreillyauto.com/site/c/detail/MAE0/C31421/01378.oap?year=1996&make=Dodge&model=Ram%2B2500&vi=1095869&ck=Search_C2070_1095869_4784&pt=C2070&ppt=C0331


Be careful if you use a local parts house, sometimes they will try to sell you this gasket and seal. It is for an application without the lifting eye.

View attachment 99280 View attachment 99281

Nick

Thanks, I'll try this. I'll let you guys know how it goes.

 

[sarchib]

Is your coolant mix a 50/50 ratio?
That residue looks way too green.

I hope so, but I'd have to look back at my service receipt from the dealer because they put new coolant in.