Oil leak from oil cooler

[triplewhite]

In the cold light of day I have been able to investigate my oil leak viewtopic.php?f=6&t=875&p=17881#p17881 a little further, and the oil is pouring out from where the oil cooler meets the mount. The oil cooler itself is kind of loose, which I discovered when trying to tighten the oil filter. Is there a way to tighten the oil cooler? Do I have to remove the oil filter? Is it likely that I need a new oil cooler, or is there a new seal I can get for my existing one?

Thank you in anticipation (again).

[gull]

Remove the oil filter. You'll see a threaded pipe that the center of the oil filter threads onto. It will have a flat nut on it that clamps the oil cooler in place. The first thing you should try is tightening that. It tends to work loose after repeated oil filter changes.

[triplewhite]

Remove the oil filter. You'll see a threaded pipe that the center of the oil filter threads onto. It will have a flat nut on it that clamps the oil cooler in place. The first thing you should try is tightening that. It tends to work loose after repeated oil filter changes.

Yep, got it, thanks again. It was this. The seal had hardened and the nut had worked loose. The seal broke and then oil poured out.

For anyone else in a similar pickle in the future, it's quite an easy fix. Took me an hour to drain the oil, remove the filter, remove the cooler (by the technique described above), replace the cooler seal with a spare oil filter seal, fit it all back up and add the new oil.

Thanks for you help, now I can enjoy New Year!

A happy one to all...

[kamzcab86]

Wish I had been online a few days ago.

These oil coolers are known to be high-failure parts. So long as you're replacing the seal, you should really conduct preventitive maintenance and replace the cooler as well; the difficult part is removing/installing the coolant hoses (there's no need to drain the oil, but it's very wise to drain the coolant... don't ask how I know ).

[triplewhite]

Wish I had been online a few days ago.

These oil coolers are known to be high-failure parts. So long as you're replacing the seal, you should really conduct preventitive maintenance and replace the cooler as well

Thanks, I'll keep a hawk's eye on it. I have a few more things under there to do pretty soon, so I may just order a new cooler too. It was tricky finding that stuff local and immediately over Christmas!

I know this is a bit of an open question, but is there anything else like that that I should look for? I've worked on and around VWs for quite a long time now, and the oil seal took me quite by surprise. Any other sneaky seals that should be replaced as I sail past the 200,000 mile mark sometime this month?

Thanks again, all.

[gull]

Any other sneaky seals that should be replaced as I sail past the 200,000 mile mark sometime this month?

Most of the oil seals that can fail won't create leaks this large, so just keep an eye for drips. The front main, intermediate, and camshaft seals can fail, but they're enough trouble to replace that you may want to leave them alone until they start to leak. Timing belt changes are a good time to address these, as some of the same disassembly is required.

You may want to consider replacing the injector seals and vacuum hoses, though. They harden over time and create air leaks that cause running problems, especially at idle. They're not too bad to do.

[triplewhite]

Great thanks for the advice. I have been having a little trouble cold starting the car recently and it was suggested it was an air leak, so I'll do some investigation.

Thanks again.

[gull]

Great thanks for the advice. I have been having a little trouble cold starting the car recently and it was suggested it was an air leak, so I'll do some investigation.

Any time you have a running problem with one of these cars the first thing to do is check for air leaks. Any air that goes in through a route that doesn't include the airflow sensor plate will lean out the mixture. This is especially true when the engine is cold, because the oxygen sensor isn't warm enough to work yet and the lambda system can't adjust the mixture.

[triplewhite]

This is especially true when the engine is cold, because the oxygen sensor isn't warm enough to work yet and the lambda system can't adjust the mixture.

Hmm, my oxygen sensor has been disconnected for nearly a year... I have a new one, but cannot fathom how to get access to remove the old one. Could this be part of the cold start problem do you think? This is probably the coldest it's been since the sensor has been disconnected.

The cold start problem is this: It will fire on the key as normal, but if I don't keep the revs up above 2k for 30s or so it will stall. I also discovered that while it is spluttering and wanting to stall if I push the gas so that the second choke on the throttle body opens, I can often save the stall, but I then still have to keep it above 2k for that 30s or so. Then it runs fine.

[Briano1234]

The day before Spray the o2 sensor with pb-blaster, or crc freeze-off, wait 20 minutes spray it again...wait 20 minutes and spray it again....let sit over night... while you are waiting over night go to your favorite auto store and get a o2 sensor socket that fits your o2 sensor.... Next morning spray your o2 sensor, and start the car, let warm up for 2 minutes... Turn off...

Remove the o2 sensor electrical plug. Working from the drivers side wind your arm to the o2 sensor, and place the socket on it.... seat it fully (if you are thin-armed, you can get it from the passenger side).... then still working from the drivers side place your ratchet on top and (remember lefty-loosy, righty-tighty) and push that ratchet to the firewall....(from the left it is pull from the firewall).

When going back with the new one.... spray carb cleaner all around the manifold, spray it good.... start the car....let it burn off, and burn off that pb-blaster....
then let cool, insert the new o2 tighten, and re-connect......PB-Blaster, CRC-freeze-off is a bad thing to get on the new sensor....BE CAUTIOUS not to get the Never Sieze on the sensor tip... only the threads.

[gull]

Hmm, my oxygen sensor has been disconnected for nearly a year... I have a new one, but cannot fathom how to get access to remove the old one. Could this be part of the cold start problem do you think? This is probably the coldest it's been since the sensor has been disconnected.

The O2 sensor doesn't start to work until it's warm, which takes a few minutes. So it can't be the culprit in any cold-start problems.

It looks like a bear to get to, but if you take off the plastic tube that connects the airflow sensor to the throttle body you can get a pretty good shot at it. Instructions here:
http://us.geocities.com/jonnyguru/vw/o2.html

[triplewhite]

It looks like a bear to get to, but if you take off the plastic tube that connects the airflow sensor to the throttle body you can get a pretty good shot at it. Instructions here:
http://us.geocities.com/jonnyguru/vw/o2.html

Thanks, that does seem a lot easier than I had originally thought!

[kamzcab86]

Cold start problem:
Check for air leaks. If the problem still persists, check the cold-start valve.