Why is my engine using so much coolant???

**s2driveruk** · 29 August 2006, 16:10

sorry to say if there is no sign of an external leak i'd suspect your head gasket leaking coolant into a cylinder maybe....does the exhaust smell acrid/sweet smelling after a run?

**BRY** · 29 August 2006, 16:26

Cracked head?
You need to find where it's going as it could fill a cylinder overnight and then hydraulic your engine.

**twoqu** · 29 August 2006, 16:33

Have to agree with the above! Only two places it can go out or in! Without any external drips or stains, the head gasket at the rear is one place to look as is the turbo coolant pump connections which often either break or go mushy. Be very careful if you examine that with the engine hot!
One possibility is that it is being vapourised. There is a hose between the block and turbo which could be split. If it sprayed towards the ex manifold it could turn to steam. Even so, would have thought that there would be some tell tale evidence!
As for the temp gauge sensor. The MFS in the water rail is the same as all the other S models (p/n 034 919 369C) as is available from Vagparts for approx Â£40 + vat. Think they are similiarly priced from GSF etc. The old 4 pin desigh has been superceeded by a three pin but other than that it functions identically.

**AndersS2** · 29 August 2006, 16:35

Originally posted by S4 Miss

Anyone got any ideas about what the problem is!?!

I had the same symptoms this summer! I finally spotted a leak after a while (right under the 2nd cylinderexit to the EM, and boy, did it drink fluid!)
Have you checked under the car if there is any signs of the pink stuff? if you jack it up you would easily see if there is any.
any hoses in bad shape maybe?

Does it smoke blue? if so there could be coolant in the cylinder as s2driveruk proposed.
I did send my car to a tuner, and told him to fix it all, so I won't know so much about it before i get it back

PS nice to see youre back on this fantastic forum

**pastures16** · 29 August 2006, 17:02

i was thinking about this the other day as mine uses a little water as above ive done many tests is it possible the water could be leaking through the turbo and into the exhaust while running

**kwlw** · 29 August 2006, 17:08

Originally posted by S4 Miss

My UrS4 AAN is using loads of coolant!

Anyone got any ideas about what the problem is!?!

Yes we do

. Sometimes cars leak only in high rpm. You cannot find where it does when car is idling.

EDIT: text below probably do not apply to your case - we had terribly cold winter recently, and maybe valve was damaged by cold and frozen antifreeze (it was prepared for -20 not -35).

Had strange thing with my 3b - there is climate control vaacum coolant valve in the back of the engine. It started to disintegrate - car started to loose fluid (which somehow was lost only on the high rpm when pressure is high). It was impossible to find out, because it leaked down on the gearbox and was vapourized on hot exaust tubing. Two weeks I was confused, what is happening. No smoke, no smell, until valve completely collapsed and I lost all fluid on the street. Had no idea what's happening, so tried to make mile to the garage (engine temp was shown quite normal, because damn sensor was dry).

Everything ended up with complete engine overheat. Don't know what consequences it took, but after cooling down, valve replaced it seems to run ok. Maybe fresh RS10w60 (which was in the engine at the moment of disaster) helped then. However some plastic parts of the engine, hoses, took thermal shock, they now feel different, more rigid, and alternator bearing started to sing replacement song ...

So if it's not filthy for you (it's really dirty job

) , try to put your hand to the back of the engine (let it cool down) from UK drivers side

. You must see white connector as guide - nearby there is a hose, try to trace it by hand to find the valve, and if it's wet - you'll need a new one, or at least check it. It's not possible to see leak usually. I've paid 30eur for new original teile.

Sau

**pastures16** · 29 August 2006, 17:42

any pics on this

**S4 Miss** · 29 August 2006, 19:03

Originally posted by AndersS2

I had the same symptoms this summer! I finally spotted a leak after a while (right under the 2nd cylinderexit to the EM, and boy, did it drink fluid!)
Have you checked under the car if there is any signs of the pink stuff? if you jack it up you would easily see if there is any.
any hoses in bad shape maybe?

Does it smoke blue? if so there could be coolant in the cylinder as s2driveruk proposed.
I did send my car to a tuner, and told him to fix it all, so I won't know so much about it before i get it back

PS nice to see youre back on this fantastic forum

Cheers Anders

A bit of history to this one. The car went in for a new recirc dump valve, they had to move some hoses, an ancient jubilee clip finally gave up whilst they were working and when i drove it for the first time after i lost all fluid. They hadn't noticed as it only leaked at high rpm.

The jubilee clip was replaced, and so i thought, was the problem. But its still drinking the pink stuff with no leak visible underneath. As I said, its passed a coolant pressure test today and the garage say no leak and no head gasket problem (had the oil changed and no sign of contamination) so i'm at a loss.

They said it could be vapourising but that doesn't help me stop using so much of the stuff! Sometimes if I've been driving it like i stole it there is a weird burning smell after...but not sweet...and definately no blue smoke...

Bah!

**Knight Rider S4** · 29 August 2006, 20:22

I have had problems with over heating on mine on and off for the past two years i am sure it is cursed or it is the way i drive...mmmmmm

anyway i had the same issue were i was putting water in her every 200miles which was a right royal pain in the **** ...ended up first time that it was leaking from the thermostat housing when at running temp so had to replace the housing and did the temp sensor to summer ,switches fan on at 87 i think.....

I would first check all the pipes when hot and see if they are hard when trying to sqeeze them if they are this means there is pressure been added by crack or leak from cylinder (top and bottom pipe on Radiator are best to check)

there is a seal at the back under the EM which i still need to check on mine as i have a small leak from the rear of the cylinder head

See if you car does this?.....(this is mine at the mo)

When you find out tell me what it is ...........lol

Good luck

**twoqu** · 29 August 2006, 20:36

Mmmm

Has the car only started using water after the replacement? What hoses did they disturb? Obviously if it was a coolant one, then it might be related. The only one I can think of in that area would be the turbo return, the one that mounts onto the top of the turbo.

**ericd** · 29 August 2006, 20:55

Originally posted by twoqu

Mmmm

Has the car only started using water after the replacement? What hoses did they disturb? Obviously if it was a coolant one, then it might be related. The only one I can think of in that area would be the turbo return, the one that mounts onto the top of the turbo.

even bigger hmmmmmmmmmm

Don't really understand why you would have to disturb/disconnect/reconnect any coolant pipe when replacing/checking dv

**Knight Rider S4** · 29 August 2006, 21:03

Originally posted by ericd

even bigger hmmmmmmmmmm

Don't really understand why you would have to disturb/disconnect/reconnect any coolant pipe when replacing/checking dv

Good point time to start asking some questions

**Briggsy** · 30 August 2006, 08:23

the culprit on mine was the water after run pump, didnt show up on any pressure test's only came to light when i placed my finger under it, it felt all moist!
come to think of it, the pump only leaked when it reached a high temp or when the pump cut in, both obviously linked!
hope yours is an easy fix

**S4 Miss** · 30 August 2006, 09:56

Thanks boys!

Calling in emergency help today....my dad!

I've got the day off to spend some time looking at it so I'll let you know if anything comes to light.

j x

Why is my engine using so much coolant???

Why is my engine using so much coolant???

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