Hello all, here's what happened to my '88 328 this evening: I pulled up outside my house after an 40 minute drive, mainly highway. The street I live on is fairly steep and I parked it, nose facing down hill, and left the engine running while I moved my other car out of the garage. When I returned to my 328, coolant was coming out of the radiator overflow hose at a very rapid rate! Engine was running hot, so I quicly jumped in and reversed it in my driveway before shutting down the engine. By now, just steam was coming out of the overflow. With a rag, I pushed downon the radiaror cap while it was still on tight and the steam stopped. Took my hand off and bach it came. I let it cool and removed the cap. I believe it is original, therefore 25+ years old. It looked ok. My questions: Are caps prone to failing? Do I have a more serious problem and the cap was just doing it's job? What coolant is recommended? Thanks in advance...
There is a cap for a Mercedes that works fine on the 328. i have had one on my 86 328 for about a year. I think the part number is posted in the cross reference thread. If not I can look through my records later. Its an off the shelf item that most parts stores have.
Not sure I understand this correctly, so please allow me one stupid question (I am french, after all, so...): Was the steam coming from the radiator itself at the front of the car, or from the overflow tank at the rear in the engine compartment? Which cap are we talking about? the one from the overflow tank at the rear? By the way, my personal opinion is, whether it was from this cap or not, it is not safe to entrust the safety of your cooling system (and therefore your engine) to an twenty-six year old cap and rubber: rubber ages, you know. Whatever the specific problem you are talking about comes from, change that cap for a brand new one... Rgds
You might not have any real problem, and the cap was just doing it's job (but no sin to refresh now as the others mentioned). Are you a fastidious coolant "bleeder", and know the system was properly full, or has it not been bled in many years? Next diagnostic steps would be to refill and bleed (when cold) then recheck if you have any problem (when positioned more level).
I agree. Replace the cap as your first fix. They need to be changed every couple of years. Also, you are very trusting of your e-brake. I wouldn't park my 308 on a hill unattended while running. The 328 e-brake may be a better system though
The 328 parking brake is vastly improved over the 308. It is a modern system where a drum brake is nested inside the disc hat, completely different from the awful 308 system. Image Unavailable, Please Login
Not wanting to look like I have knowledge in mechanics...I don't, and defer to competent people like Steve in this matter, but: A simple thing to check is, after each service or coolant refill, not forgetting to drive the car for at least thirty miles (50 kms for us metric folks) with the heating FULL ON. The heating circuit, when not operated regularly, holds a lot of air bubbles; it is not a bad idea to have coolant circulated here from time to time. I discovered that, if not done after service / refill, the heating circuit will expel the air it holds in the main cooling circuit, and the bubbles makes the car throw some coolant overboard after being switched off. So check this form time to time: operate the heating at least every three months. Both my 328 ('89 GTB; '89 GTS) are happy with the level of coolant in the overflow tank, measured when the car is cold, as exactly in the middle of the tank, right on the crease between the two parts of the tank (or 6cms below the upper ledge of the neck, exactly as per factory Owner's manual); Anything above that, the car will throw it overboard. Rgds
Yes, the radiotor caps are prone to fail because of old age, rubber like Nerofer mentioned, I've replaced mine with an improved one and on my history it shows they were replaced four times... (89 - 328 GTS) this can happen to any older car... everything should be ok because you did not drive without coolant water if I understood correctly... Oh and,,,its a good idea to flush/replace coolant with annual services, Febi-Bilstein Coolant/Antifreeze a German product is fantastic and is recommended by many petrol heads, even the Ferrari Agents uses...but there are lots of other good brand coolant products out there... cheers John
I replaced the original cap on my 87 right after I got it with a higher rated new cap I bought from Ricambi. No problems of any kind since. Keep the old cap in case you want to show your car...replacement rad. cap is a point deduction.
Aloso, you might have the old .9bar cap that are now replaced by the 1.1bar. Yes, bleed the system then change the cap with the 1.1 bar which is about 15lbs.
Nerofer, thanks for your insight. Sorry, I should have clarified. It was from the overflow tank at the rear in the engine compartment.
I don't trust the e-brake on any of my cars! Whenever I have to do this while swapping cars around, I will also turn my wheels into the kerb as a back up, always ensuring my rims are never damaged of course
I believe the coolant was replaced at the last service, about 18 months ago when I bought it and I haven't done anything to it since. Is it difficult to bleed the system? I have not really attempted any DIY as yet...
New 328 to me, prior owner had dealer work including changing radiator cap. Still, water on floor after every drive. After 3rd drive it now seems unusual that equilibriumi not found as i have add no water yet continuous floor is wet. I remove radiator cap and the black seal falls off and I look to see these cracks. Radial cracks There is a dealer recipt of 600 miles/Aug 2022 before shows this part replaced so for sure is OEM. Photo shows has 06/21 production date Please take care. I just ordered 2 radiator caps, 2 thermostatics with bleed brass bolt,, H2O pump, belts, radiator fan thermal, CU washers but also will flush with Prestone flush before installing these new. Best to start new now Image Unavailable, Please Login Image Unavailable, Please Login
Very common. Its why I never use Italian radiator caps. When I was shop foreman at the largest dealer I made the parts department give service department only Stant brand caps. We had way too many comebacks for Italian radiator caps. Unmitigated garbage.
