Head Gasket repairs Additive!!

[BelfastBill]

Just wondering if any of the advertised head gasket sealants actually work, my son has a water leak from somewhere and we can't find it, just loosing water and no sign of oil in the revivor or leaks showing on the ground and the car is running great. So I'm thing it might be blowing across the head into the exhaust port or something. I have heard that the Barr's of Steel to steel additive are good but looking for reliable information on this,so if anyone knows please let me know. Not wanting comments from people who think they know just people with experience.

Many Thanks'
Bill.

 

[bob6600]

Have you checked the oil to see if there is water in there? I had a leak in my W210, suspected head gasket. I tried an additive, did nothing. There were some concerns that it could clog up but I tried it anyway. Eventually took the head off and the gasket looked fine, Re-did it anyway but the water still escaped into the oil so it was a problem in the block somewhere. What year is the S Class? Might help diagnosing the issue.

 

[Shadychris]

I've used these 'magic' sealers before on old bangers or as an emergency 'get me home'. YMMV if it's just a small water leak or very small compression leak it may well hold for a while. However I wouldn't touch the stuff with a barge pole on a decent car. When you come to do the job properly at a later date - which you (or someone else) surely will, there will be a hell of a mess to clean out.
One other possibility could be heater matrix or pipework inside the car - check your carpets in footwells under dash etc for signs of damp\smell of antifreeze..

You could also have a pin hole leak in the main rad that is only leaking when the car is hot and cooling system pressurised. These aren't always easy to spot as you wont get water dripping on to the ground when its cold.

 

[Shadychris]

Believe you can also get your coolant tested now by a garage to detect the presence of exhaust carbon monoxide in the coolant. Maybe possible to buy a kit yourself which could give you further clues..

Edit: Yes you can...

COMBUSTION LEAK TESTER KIT CO2 PETROL HEAD GASKET TEST FLUID BLOCK 100ml | eBay

If the fluid turns YELLOW or GREEN, a combustion leak is present. Change the color of the liquid reaction to yellow (petrol engines, LPG) or green (diesel). Works with petrol, LPG and diesel engines.

www.ebay.co.uk

 

[219]

I used K-seal on my 190E when it had CHG problems ; it stopped the external leak for as long as I ran that engine , but I still saw small amounts of emulsion in the water .

I replaced the 1.8L engine with a 2.3 , still M102 , which was a huge upgrade that transformed the car .

 

[steveq]

What is your son's car?

Why do you think it is a head gasket?

 

[Smiley]

I have also used K Seal and successfully sealed a small external leak on a 124 diesel CHG. I did more than 100k miles after using the K Seal so it is definitely more than a "get you home" repair. The K Seal did leave a residual copper coloured "mess" in the expansion tank. I decided to try it based on a known fault condition; I would not put it in on the basis of hope. You need to find the problem first - either by pressurising the system or using a sniff test or both. Depending on the car it may be more likely to be a water pump or heater or rad than the CHG. Then you can make an informed judgement.

 

[BelfastBill]

Its a Peugeot 208 and not sure it's the head gasket just can't find where the water is going car is starting and running fine.
Thanks to everyone for their help.
Bill.

 

[steveq]

Its a Peugeot 208 and not sure it's the head gasket just can't find where the water is going car is starting and running fine.
Thanks to everyone for their help.
Bill.

Hi Bill,

I can't help you on the Peugeot specifically but if it was an MB with an OM651 engine, I might have been able to assist.
On my E Class with the OM651 engine, I had a coolant leak which I couldn't find.

I eventually did find it by looking when the engine was cold. I found a small seep from the water pump.
Previously I had always looked when the engine was hot and the coolant evaporated immediately so no leak was visible.
It was a small seep when the engine was just at tickover but must have increased when the revs increased judging by the amount of coolant loss.
Changing the water pump cured the leak.

Not sure if that has any relevance to your issue.

You can get dyes to put into the coolant that stain the location of the leak even when the coolant evaporates.
Maybe use a food dye to do the same thing?

 

[steveq]

I also just had a thought that the water pump on the Peugeot is probably behind a cover as it is driven by the the timing belt?
It could be the culprit but very difficult to spot.

If it was the head gasket i would have thought that you would have other symptoms -- overheating, difficult to start, sludge in the oil, etc.

 

[Denis O]

Another positive view of k seal. I used it on 2 P38 range rovers which always leaked from the heater o rings. It was either the dash out or chuck in some k seal. I did the latter and it worked on both vehicles for many miles.

 

[BlackC55]

Those sealants are a pain. I'd avoid them as much as you can. The blockages i have seen all over the cooling system on MB's caused by this stuff is shocking. Look at the heater matrix......

 

[a111r]

Minor leaks can be an aged, weeping O ring on the thermostat housing.

 

[Stocious]

Do not use an additive to stop a leak, it goes everywhere, especially your radiator if all ready in bad shape, think of the mess the mechanic has to deal with after pulling head if that is the problem, hours of cleaning and flushing to prevent issues with work done, get a sniff test kit, and a coolant system pressuring kit, water leaks can be notorious, you can see where they drip from but the source may be concealed or not at all possible to see

 

[Stocious]

Start the car and get it good and hot stationary with a fully roped up cooling system, let it sit overnight, watch the exhaust for steam on first start in the morning

 

[Dickster]

Do not use an additive to stop a leak, it goes everywhere, especially your radiator if all ready in bad shape, think of the mess the mechanic has to deal with after pulling head if that is the problem, hours of cleaning and flushing to prevent issues with work done, get a sniff test kit, and a coolant system pressuring kit, water leaks can be notorious, you can see where they drip from but the source may be concealed or not at all possible to see

get the system pressure tested

 

[MJJ]

Its a Peugeot 208 and not sure it's the head gasket just can't find where the water is going car is starting and running fine.
Thanks to everyone for their help.
Bill.

I recently solved an identical issue on my son's 207. Turns out the expansion tank pressure cap had failed, but it was only ejecting coolant when the engine was both at full temperature, and running at medium to high revs. Because my pressure testing kit involved replacing the cap with a pressure bung, the system always checked out. However, after driving 5-10 miles in the car, the expansion tank was empty.

A new rad cap for £15 solved the problem. In my case, the diagnosis was compounded hugely by buying a cheap cap from eBay that turned out to be faulty also. Genuine Peugeot cap fixed the problem instantly.

Martin.

 

[horatio]

Another positive view of k seal. I used it on 2 P38 range rovers which always leaked from the heater o rings. It was either the dash out or chuck in some k seal. I did the latter and it worked on both vehicles for many miles.

Risky! Those beasts were known to blow HG’s and crack the blocks when they overheat. IIRC there was a short cut for replacing those o-rings, cutting through a plastic duct then sticking it back together or something. I had it done on mine.

I tried to clean out k seal from a discovery, was not fun. The only circumstance I would use it would be to limp an old banger through a few more months before scrapping.

 

[BelfastBill]

Thanks all.