Yellow sludge

slipss

hey ppl I was wondering if any1 there that knows a bit more about cars could help me please. I went to have a look at a 2000 hyundai coupe I was thinking of buying and everything seemed fine exept for one thing. when I opened the oil filler cap there was this bright yellow sludge on the inside. I was just wondering if any1 knew what it was, what could have caused it and what would be involved in fixing the problem if i chose to take the car. any ideas will really be appriciated because the guy said he canb only hold the car another two days thanks a million.

BrianD3

This yellow stuff underneath the cap is caused by oil and water mixing. This is very common if the car gets a lot of short journeys and never warms up properly. This results in moisture staying in the engine. This is no big deal and is very common.

However it coudl also be a sign that the car is not warming up properly eg there could be a problem with the thermostat. If the car is driven for long journeys and still has this stuff under the cap then that might be a cause for worry.

Also, if you see the same yellow stuff on the dipstick and/or oil in the coolant expansion tank then that could be a sign of a blown head gasket which is a serious problem.

kluivert

I didnt read the post fully sorry.

Blown Head Gasket for sure. For a car of its age its been driven hard.

bazz26

slipss wrote:

hey ppl I was wondering if any1 there that knows a bit more about cars could help me please. I went to have a look at a 2000 hyundai coupe I was thinking of buying and everything seemed fine exept for one thing. when I opened the oil filler cap there was this bright yellow sludge on the inside. I was just wondering if any1 knew what it was, what could have caused it and what would be involved in fixing the problem if i chose to take the car. any ideas will really be appriciated because the guy said he canb only hold the car another two days thanks a million.

If that sludge looks like Mayonase then this could be a sign that either the head gasket is blown or it is on it's way out. Either way a head gasket can be quite expensive to replace.

I would expect the garage to replace this first if you are buying from a dealer.

Green_Martian

Walk away.........sound like the Head Gasket

De Hipster

Gkelly2002 wrote:

Walk away.........sound like the Head Gasket

Run! I'd definitely consider it an unhealthy head-gasket sign.

BigCon

Whoa there - yes it may mean that the head gasket is gone or on the way out, but it's just as likely to mean that the car hasn't been serviced in a long time - oil change could cure it.
Anyhow, don't buy it woithout checking it out further.
Take the car for a drive and make sure it's heated up. Then leave the car running to see if there are any temp problems. Also remove the cap off the water container (carefully as it's hot) and see if there is any air bubbling back up (indicative of a blown head gasket).
If all of these are ok, then you might be alright - get a mechanic to check it out if you're not sure...

BrianD3

Whoa there

Yeah, i suggest people read the first paragraph of my first post. Mayo on the filler cap is not a conclusive sign that the head gasket is gone or going. In fact, nearly all cars that are used for very short journeys will have some mayo under the filler cap and it is no cause for concern. I wonder how many head gaskets are replaced unnecessarily because of this. I'd say it's a favourite trick of unscrupulous mechanics who'll tell you your HG is gone at the first sign of mayo on the filler cap and will then proceed to make a "sucking in air" noise as they give you a quote of 800 quid to change the gasket :mad:

AMurphy

If it is a Hd Gasket, check a few more items.
Look for oil in the rediator coolant.

Look for lots of steam in the exhaust, even when hot, water leaking into the exhaust.

And when driven hard and let to idle, check if it is "boiling" or bubbling and generally losing water.

If the owner indicates it has been driven a lot and in reasonably long journies, eg 10 miles each way.... that's enough to heat a car. Then I'd be wary.
if it never went more than 2~3 miles and stopped again. would most likely be lack of driving.

You can check for exhaust gasses inthe coolant, or rather a good garage should be able to do it for you.

forgot to mention, inspect the plugs. If they are all the same color good, if 3 are black and one white I'd suspect it is being washed with coolant.

johnplayerblue

Hey!
My brother bought a 1L 97 seat ibiza some time back with 10000mls on the clock and when we got it home we found the same thing under the the filter cap, what made us check was the fact that she wasn't thicking over very well and would cut out after 5mins or so but was driveing very well.
We gave her a good going over cleaned away all the yellow sludge replaced the filter and flushed out the engine and put some clean oil in and now shes thicking over and running like new.
The car was not looked after AT all and was in a bad state inside but cleaned up very well and id say the engine never got much attention at all. Now shes has an Nct for the next 23mths, yellow sludge while not a good sign is not the end of a cars life!
I Hope.......