My 1995 Vanden Plas has a strange leak that I cannot find. I noticed the coolant light come on the other day so I put coolant in the reservoir. One Plastic jug filled it no problem. Off I go, coolant light out. 2 days later the same thing happens again. One more plastic jug..no worries. The strange thing is I see no leaks anywhere. I look on the ground no puddles. Maybe I need another reservoir? Seems to happen when Im on the freeway. I don't want to have to continually add coolant all the time.

Any ideas?

Thanks!

 

Go to your prayer closet and pray very hard that it is not the water rail gasket(s)
I'm currently mending a leak at the aft water rail gasket right now and the it is a heinous job!
But in this case, you could see coolant dripping off the oil pan on the left side.

 

Years ago I searched and searched for a minor leak on my 1995 XJR. In that case I could *smell* a coolant leak but simply couldn't see one.

In the end it turned out to be the gasket between the thermostat housing and the cylinder head. Very slight drip

Cheers
DD

 

had a strange leak years ago on an X300 that took a while to find...

it was one of the hoses going to the heater matrix, when the engine was rev'ed the engine moved on its mounts (rocking motion) exposing a minute split/hole in the hose.....thinking now it could have been caused by worn engine mounts stressing the hose but maybe worth a look if you can't find a puddle and/or have already done tests for leaking head gasket etc

 

My 96 Jag Vanden Plas had a coolant leak last year. I could not locate the leak for quite some time. Kept filling up the reservoir and the low coolant light would go away. Finally after a lot of looking, my friend found a micro hole on the upper radiator hose. My theory was that at some point a mechanic had a slip of a screw driver and pierced a mini hole in the hose and it gradually became worse.

With the car engine off and when cold he squeezed hard on all hoses and saw a minute amount of coolant come out of the hole. Also the leaking coolant was dripping on the hot engine and burning off, hence no coolant on garage floor.

Hope this helps.

 

a pinhole leak in the radiator might do it, as the heat on the radiator tends to evaporate the slight leakage as it occurs, rendering it almost invisible. Pressurising the system is the way to test for a leak, although it might be tempting to simply pour some sealant into the system. This would be perfectly adequate for a small leak, although purists will shudder!

 

I found the leak and its pretty bad. Not sure exactly where its coming from...I top off the reservoir and start the engine. I reved it a few time to see if I could see where the leak was coming from and saw a lot of coolant coming out from behind the engine I think its the manifold? It seems like theres a seal back there where its coming out from. Anybody know what that part is? Is this something I could repair? Thanks!

 

There's a plate on the back of the head. I don't know if it seals against coolant, but possibly. I recall seeing procedures for renewing its seals in JTIS while looking for something else. Check the hose coming off the pipe at the back left of the head that feeds the heater matrix. A split in tbe right spot on that one could shoot it down the back of the engine.

 

Hi Thanks!
Yeah I cant figure it out..does coolant actually go thru the intake manifold? Seems like
thats where its coming from. I also reved the engine and put my hand there and it seems to come from that seal at the end of the intake manifold

 

Yes, the intake manifold has a coolant hose port or two on it. The plate on the back, and the pipe that feeds the heater matrix I was speaking about above, are actually attached to the HEAD not the intake manifold.
There's always the water rail, mounted to the left side of the block and hidden behind/beneath the intake.... that I warned you about in my first response. It's a heinous job, just finished one tonight.... you'll need two water rail gaskets and an intake gasket, 3 elbows on each arm, magnetized fingertips, teeny-tiny hands and a boatload of patience!

 

The leak is def coming from the intake manifold. Its either the gasket or the port you mentioned. I put my hand down there again and felt the water coming from the port.

 

The intake manifold gasket only seals air, preventing vacuum leaks. The hose ports on it are small and near/on the throttle body. I'm beginning to suspect you do actually have a leak at the water rail gasket.

 

Maybe so....when I put my hand where the port is I feel all kinds of coolant squirt out from that area (my hand is right where the port is). Wish I could see it better its on the right side of the intake manifold.

 

I have a whole other car for parts...guess Im gonna have some fun!

 

Resolved! Turns out it was one of my hoses, the spray would hit the manifold and then bounce off! I feel so much better!

 

any diy on replacing the hoses?

 

Which one? Or all? I've posted on it...try to dig you out a link in a bit.

 

All