kevinlieb

I had noticed some wetness when parked for a while on the front right corner of the car (passenger side in US). I finally got a chance to jack it up and stick my head under it today and I clearly saw coolant leaking down the right side of the radiator. Its not coming from the top radiator hose as far as I can tell (its tight up there) and the plastic bits that make up the right side of the radiator have some dampness on them. It does not seem to be coming from the drain plug, it seems higher up.

The drip is steady but is just a drip, so far.

Is this a common place for these radiators to just fail? Do I have any options other than to replace the radiator? Anything else that might be leaking around there other than the radiator itself?

Its an '88 S4 auto.

Podguy

could be leaking from the o-rings on the oil cooler. You could see it the threaded rings on the cooler are loose. Pressure testing is one option. There is a tool that attaches to the radiator cap and puts a little pressure into the system. I made one from a old radiator cap, gauge, rubber plug and bicycle pump.

mickster

Probably failed radiator end tanks. Not uncommon. Get a powerful light and shine it from the top and you may be able to see the leak easier there where the metal tabs meet the end tank.

If that's it you can either buy replacement end tanks and tackle it yourself (a number of threads including the bending/unbending of the tabs without breaking are on search), bring to radiator shop to put on (who know how to handle Behr) or buy a new or used radiator.

End tanks are $85 (IIRC) at 928sRUS for $85 and include new O rings, gasket and plug. Not sure if the other big 2 sell the tanks. New radiator north of $700; Used $500.

Mrmerlin

you need a new end tank buy one and take the radiator to the rad shop that will install end tanks you only need the right hand side
NOTE since you have an auto you will also need the 2 sealing o rings for the cooler.

kevinlieb

I didn't realize the metal tank and the ends were separate pieces. It definitely seems like where the radiator meets the ends is where it is leaking.

I guess when I get it all out I'll see how it all goes together. But is it possible to try the auto trans oil cooler o-rings before I take the whole radiator out?

Podguy

The two plastic end tanks are crimped to the aluminum raditor body. There is an o-ring that seals the end tank. The end tanks can crack as well. New end tanks are about $100 and should be installed by a professional radiator shop. When replaced the radiator can be rodded out to give better flow and cooling.

The internal coolers are installed inside the end tanks. The cooler can develop internal leaks that spills coolant into the cooler or oil into the radiator. This does not appear to be happening in your case. The cooler is sealed from the end tank by an internal o-ring. The cooler is thing held in place with two very large nuts over the outlets. These can come loose and develop the kind of leak you are experiencing. I would no tighten them too much but it they are loose they will snug up and might end your problem.

After that the next approach is to pull the radiator and take it to a good radiator shop to be pressure tested and repaired.

kevinlieb

I have a line on a radiator, part is 928-106-023-20
Does anyone know if that is the right part for a '88 S4 auto?
Pelican says it is "Radiator, No Cooler, 928 (1987-95)"
I can't get my head under my car right now to see if that is the part # on the bottom of mine...

kevinlieb

Actually seems to me this is the wrong part. I have a cooler ports on the left and right side of radiator. One auto trans and one oil? I don't know.

Here is a nice deal on a new radiator if anyone is looking:
http://www.ebay.com/itm/251116775750...84.m1423.l2648

kevinlieb

This has been quite an ordeal.
Turns out the core of the radiator itself was leaking. Good thing the radiator shop found this out before they replaced the side tanks. Then I got a new radiator from a respected source and turns out it is leaking too. I found this out after getting everything all back together, tightened down and was taking it off the jackstands to take it for a test drive.

I am assuming the respected source will make good and replace the radiator but I still have to go through the trouble of getting the bad one out again. Now I think this time I can do it in 30 minutes or less after all that "practice" and loosening up the oil and trans cooler hoses. Another week delay waiting for a replacement to arrive or have the replacement radiator fixed at the seller's cost.

Just venting. Gotta love complicated classic cars!

kevinlieb

My Saga gets Sillier.

I took the old radiator to a more reputable shop, San Carlos Radiator, thinking that the first shop I took it to just really didn't want to do the tank replacement. They tested my old radiator and found it to be just leaking from the tank, which was my original suspicion. They fixed it for $108.

So my original radiator is back in, no leaks! I just have the replacement new radiator on its way, which I really don't need anymore. I will probably keep the new radiator as a spare, just in case this one fails again.

Moral of the story: go to auto repair shops you know and trust, or that have a known good reputation. Lazy incompetence is lurking everywhere!

nc_growler

Glad to hear you got it fixed right. Definitely helps to get a reputable shop that has worked on our radiators.

Sounds like you got a fair price on the end tank replacement as well. That's close to what I paid to have mine repaired here as well.

Bill Ball

Kevin:

Glad to hear this. That makes two shops in the Bay Area who can fix Behr radiators properly.

tveltman

I believe I took mine to San Carlos radiator when I accidentally put a screwdriver through the core on the morning of SITP. The guy recognized it immediately as a 928 radiator, and the fix was cheap, guy did a good job.