Coolant Leak

[RickyD 0]

Good Afternoon All,

 

I've had my 1.9 GTI for just over a week now and I've only driven it four times and it appears to have developed a coolant leak. I've check all the usual places and it's not the radiator which is a good thing.

 

I believe that the water is coming from the underside of the coolant resevoir, so it may just be a loose connection. I will nip it up when I get home and see if it makes any difference.

 

Has anyone else had this concern?

 

The joys of 20 year old car ownership

 

Cheers

 

RickyD

[Anthony 1,000]

If it's a Phase 2 car with a black squarish expansion tank, it could be that the seal on the level sensor is leaking as that's on the underside.

 

Also, check that it's not just spitting coolant out of the overflow on the top and running down the back of the tank, dripping off the bottom thus making it look like a leak.

[RickyD 0]

If it's a Phase 2 car with a black squarish expansion tank, it could be that the seal on the level sensor is leaking as that's on the underside.

 

Also, check that it's not just spitting coolant out of the overflow on the top and running down the back of the tank, dripping off the bottom thus making it look like a leak.

 

Thanks Anthony,

 

I believe my car is a late Phase 1 car. It was registered in January 1991 and has the older orange indicator rear clusters. Going back to the coolant reserovir it's a clear colour.

 

It appeared to be low on coolant when I bought it last weekend so I topped it up with de-ionised water/antifreeze mixture and today is the first day it's decided to leak. I may have over filled it, therefore I will keep an eye over the weekend as I've topped it up again.

 

Upon checking it before it looked as though the leak was coming from the pipe on the underside.

 

Cheers

 

RickyD

[Tom Fenton 1,526]

You will just have to track it down buddy, these cars are 20 years old now so it could be clips, hoses split or perished, etc etc

 

I am sure you will track it down, get the engine hot and then have a good look round as this puts the system under pressure which usually will expose any leaks. It could just be a hose that is on its way out and is weeping, but better to sort it now before it lets you down altogether.

 

Also have a really good look round the rest of the coolant hoses, as if they have never been replaced the chances are they will be well past their best.

[RickyD 0]

Thanks Tom,

 

I appreciate you support. I checked the hoses after my journey back home and I think it may be the water pump. I have a Haynes manual which I bought from ebay the other day.

 

Is the water pump next to the gearbox? It well be a perished pipe, as when you squeeze the main pipe there's a small leak coming from under the gearbox area.

 

I will have another look tomorrow or Sunday if I get a chance.

 

I also fully appreciate that it's a 20 year old car and it's done really well to last that long.

 

I'm enjoying ownership alreay and I get more people looking at the car than my old MK2 Seat Leon Cupra 2.0T which had 19" BBS CK's, Milltek exhaust, Aero Skirts and rear spoiler.

 

As I've got a 3 year old daughter I've gone slightly sensible and bought a brand new Audi A6 2.0 TDI S-Line Lemans 170bhp last September as it's a real nice piece of kit with all the toys.

 

Cheers

 

RickyD

[allye 530 3 Cars]

The water pump is at the other end of the engine to gearbox, sort of next to the alternator. As for the leak under the box are you sure its not the top hose, thermostat to radiator pipe perished and leaking down under the box? This pipe was fooked on my XS when I got it.

[RickyD 0]

Cheers allye. I was slightly confused when looking though the Haynes manual. I know the timing belt/alternator are at the opposite side to the gearbox, however I'm not too sure what the component is called where it's leaking.

 

Any ideas anyone?

 

Cheers

 

RickyD

[allye 530 3 Cars]

If its leaking at the gearbox end then as you said hoses around the header tank, or thermostat/housing/top radiator hose.

 

Surely you can see where it is comig from looking under the bonnet when the engine is running?

[RickyD 0]

I'll have another look tomorrow. I more of a car fanatic and detailer than a mechanic to be fair. I know a few people in the trade, so if I get stuck I will seek assistance from them.

 

To be fair if I'm going to get the cambelt changed, it might aswell replace the water pump.

 

Cheers

 

RickyD

[RickyD 0]

I've had another look this morning and I don't think I'm any further forward. I took one of the smaller diameter coolant pipes off as it looked to be perished. Turns out it wasn't.

 

I take it the component below where the distributor is, is the thermostat. Do thermostat's leak if they are faulty.

 

Cheers

 

RickyD

[welshpug 1,627]

If the cooling system is as per most P1-1.5 cars then below the distributor you'll have a housing bolted to the thermostat housing that has the SAD attached to it as well.

The ecu coolant temperature sender is screwed into the side of this, one coolant pipe comes from the heater matrix to the rear, then a short S shaped one comes off this to the side of the thermostat housing.

 

On later cars this housing is not present and the heater matrix hose is longer and attaches directly to the thermostat housing, and the SAD bolted directly as well, the blue ecu tempeature sender is located in the rear side of the thermostat housing alongside the Dash gauge and warning light sender/switches.

 

Off the front of the thermostat housing you have the top hose, as well as a small hose that normally goes to the throttle body (attached to a small takeoff that has a bleed screw on it as well)

 

Then another hose back from the throttle body to the expansion tank.

[welshpug 1,627]

[RickyD 0]

Cheers welshpug, I think I may have fixed it as after a run out today there was no more leakage.

 

I don't have faith that it is fixed though as I don't really have much luck with older cars. My main drive is a 60 plate Audi A6 and the Pug is a lot more fun.......

 

Many Thanks

 

RickyD

[RickyD 0]

Nearly a week later and to leak has re-appeared. The car has been used a few times this week with no leaks and for it to re-appear seems very strange.

 

Hopefully I can investigate over the weekend again.

 

Cheers

 

RickyD

[pug_ham 242 3 Cars]

The hose that runs from the thermostat housing to the coolant temp sensor housing as posted by welshpug have a good tendency to perish, split & leak, especially on a 20 year old car.

 

Also, a split top hose could cause this although this is likely to be quite a big leak.

 

Graham.

[jackherer 543]

It could be a new leak, I've had that several times, you fix one leak and then the next weakest point goes as the pressure is higher. What is the overall condition of your coolant hoses? Might be time for a new set from BBM...?

[RickyD 0]

Took it to my mates Dad's to set a day for him to look at it before the MOT and he's fixed the coolant leak.

 

It was the top hose that needed tightening up.

 

Cheers

 

RickyD