coolant mystery

[wayneeo]

hi all,

i have a passat 2.0 130bhp and several weeks ago the temperature gauge started working intermittently or would go to 90 then drop to 0 again. i then started to also loose coolant but cannot find any leaks anywhere, i have to fill the bottle up every couple of days. now when i start the car for the first 5-10 seconds it runs roughly as if firing on only 3 cylinders then it corrects itself and runs smoothly would this all suggest the head gasket is going?

thanks in advance for any advice
wayne

[martin1810]

Have a good look round the radiator for signs of leaking. The rough running could be because you need a new temperature sensor. Of course you could have head gasket problems. Lets hope not.

[cazyp]

Have you checked for water in the oil - mayo looking sludge in the oil filler cap?
Check the lower corners of the radiator for rust=corrosion=small hole.

[ddave05]

As suggested above you need to eliminate whether it is a leak or a head gasket problem.

What you can do is when you park the car overnight, put some plain paper or newspaper under the engine bay (tape it down with masking tape) and inspect it in the morning. This will not only tell you IF the car is leaking coolant, but also WHERE the leak is coming from. No water means it could be a headgasket problem which means it could cost BIG money.

[cazyp]

As suggested above you need to eliminate whether it is a leak or a head gasket problem.

What you can do is when you park the car overnight, put some plain paper or newspaper under the engine bay (tape it down with masking tape) and inspect it in the morning. This will not only tell you IF the car is leaking coolant, but also WHERE the leak is coming from. No water means it could be a headgasket problem which means it could cost BIG money.

Good advice but you should remove the undertrays as the small leak hole in the rad generally only leak loads once under pressure with the engine running. Stood overnight it wont lose a lot at all and the under tray will catch/relocate the water droplets.

[wayneeo]

thanks for the advice, ive checked all over and i cannot find any leaks? it only seems to idle rough from cold when warm it starts and idles fine.........gooing to replace temp sensor this weekend and see if that improves things a little but the water is a mystery.....

wayne

[cazyp]

thanks for the advice, ive checked all over and i cannot find any leaks? it only seems to idle rough from cold when warm it starts and idles fine.........gooing to replace temp sensor this weekend and see if that improves things a little but the water is a mystery.....

wayne

If you're still losing water then 99.99999% sure it'll be the radiator... Common problem, lower corners rot. Mine went at approx 3 years old/110'000 miles.

£200 at a garage approx or around £90 for the rad DIY.

[wayneeo]

hi all

just to let you know replacing the temp sensor seems have cured the idle problem too!!! thanks for the help
wayne

[cazyp]

hi all

just to let you know replacing the temp sensor seems have cured the idle problem too!!! thanks for the help
wayne

Are you saying fitting a CTS has fixed the water leak? :confused:

[wayneeo]

no, alas the coolant loss is still a mystery but replacing the sensor seems to have sorted the rough start and idle part of my problem. still confused by the coolant loss as the really doesn't seem to be any evidence of a leak

[cazyp]

no, alas the coolant loss is still a mystery but replacing the sensor seems to have sorted the rough start and idle part of my problem. still confused by the coolant loss as the really doesn't seem to be any evidence of a leak

Ah I see.
Trust us that it will be a very small weep from the bottom corner of the radiator. You'll need to remove the front trim to inspect. When you top up make sure you use the right concentration of G12 coolant.

[wayneeo]

just to let you know the radiator was the problem, and it was in the bottom corner too!!!!!! thanks for all your help..

wayne

[cazyp]

Lol. They catch a lot of people out - hard to see the leak. Glad it's all sorted.