Hey gentlemen! I am getting to know my 84' 928S, had her about a month........and while I have owned English cars, this is my first German. Been enjoying it very much I must say.

So I have from what I can tell the classic Radiator Issue. Passenger side Top, where the Plastic End Cap meets the tank there is a leak...............but only when I shut down the car, when it is running, she seems fine. So the fix is a new side cap and seal, and from what I understand unless you have the proper tool for the metal tabs and for compressing the End, a Radiator shop would be best right?

Why the leak when the car shuts off? Pressure I assume? Maybe I can just drive it 24/7

Anything I can do in the meantime to drive her (will have her in during the next week to asses the leak)?

 

Don't know why doesn't leak when running, but when mine leaked at the same spot, I drained some antifreeze out so the area would be dry and then used JB Weld epoxy for a temp fix until I could get the radiator out for repairs. It worked great.

 

Yeah, I hear ya Glen. The PO seems to have had the same thought, there is a bit of JB Weld in the area that is leaking, it looks pretty worn by now. I might try to re-patch his work, but still wondering why the leak when the car gets shut down, not while it is running???????

 

you can do this repair yourself.
it you have get a few of the long woodsman clamps.
Use a torch on the end of the tabs to heat the metal and then bend the tabs only enough to be straight. Remove the tank and clean out the sealing groove heat the tabs again install the end tank with the oil cooler, if it has one, and cut off any other plastic parts that dont belong on the end cap.
Put it together and clamp it this will hold things tight the tabs should be tapped down with a small hammer and smooth piece of hardwood

 

Upon some further investigation, I noticed that two of the metal tabs on the passenger side facing the engine are sticking out, not bent in like the other tabs. They are about 2 inches down from the top of the radiator. Could this also be a source of the leak? Or would there be enough pressure from all the other tabs to make the seal?

Also when replacing the Plastic Ends, should I just replace the passenger side? The drivers side looks clean, should it be left alone? Or is it best to replace both ends while the Rad id out? Sometimes I wonder if it better to be left alone if there are no leaks................or maybe better to replace for
preventative measure?

Any thoughts.

Thanks...
Shawn

 

Shawn,
I have plenty of the end tanks and seals in stock if you need them. $75 a cap including the seal.
Roger

 

Thanks Russ. I will have to take you up on that I think. What is the best way to contact you?

Do you think it best to replace the troublesome passenger side only............or better to do both. I have not heard or seen any posts about the driver side ever causing an issue, only the passenger. So that leads me to believe only the passenger would be needed?

Shawn

 

It's so easy to get the radiator out I'd just fix what's broken and leave well enough alone.

 

Here is how I did it..., still holding.
I found it difficult to bend the tabs (even w/heat).

https://rennlist.com/forums/showthre...hlight=no+tabs

 

Yep, very easy to get out, less than 10 min..... I drove to my local shop ( after calling and making sure plastic caps was in stock), and they made it, and gave it a pressure test + paint in 3 hours, so it went back on same day. Take's maybee 20 min to put back on.....incl new fluid...

 

Only fix/replace the passenger side tank unless you KNOW the driverside is leaking. The tanks crack due to age and also the fact that there is an air pocket in the top of the tank that cant be removed due to the location of the internal fins, you can see it on the old tank indicated by a white line inside the top of the tank

 

Thanks guys. sounds fairly easy.

I read the thread on the Nichols Site on removal (still waiting on my WSM).
So just the fan housing comes out,not the fan right? He also says something about
wires on the bottom of the fan? Is he speaking of the cooling fan or a the AC fan?
Does the AC Fan have to come out or get loosened?

FYI.........I have an AT, so will have the extra lines to remove.
Are there any threads or links that might have some pictures on the removal process?

Thanks for the replies!
Shawn

 

There are always unbent tabs opposite where the cooler connections are for some reason. You will need 27 & 32mm open wrenches to counter hold the cooler adaptor and undo the cooler pipe nut. Remove fan shrouds first - two screws at bottom, two bolts at top. Remove temp sensor at left front bottom of rad, it might snag on way out otherwise. AC condenser can stay in ok. Be ready to catch oil from coolers - fair bit from engine, not so much from AT, in my experience.
jp 83 Euro S AT 51k, doing rad replace now.

 

It leaks when you shut it off because the water temp goes up from heat soak. Combine that with no flow from the water pump and pressure is higher a few minutes after shut down then when it's running.