New Project! 87 300TD - Page 10 - PeachParts Mercedes-Benz Forum

vwnate1 · #**136** 07-03-2023, 11:06 PM

I found that if I connected every single 3/8" drive extension in my various tool boxes then a knuckle on the socket, I could get them loose pretty easily .

ah-kay · #**137** 08-06-2023, 10:09 AM

Quote:

Originally Posted by ah-kay

Don't know how the OP is getting on with the car after dumping considerable effort and money in it.

Anyway, I put the money where my mouth is. I just use Blue Devil sealant on my 1987 300D. It has 410k miles. The radiator bursted at 400k while climbing Los Angeles national mountain on I-5. Very steep and long grade. Car overheated but I think I stopped in time. Changed out the radiator and car did another 10k without issues until 2 weeks ago. It overheated and I did the radiator overfill test and found the head is done for. Coolant overflowed whenever car is run. Long story short, use Blue Devil sealant and the cracked head is sealed. It passes the overfill test and did about 300 miles so far. Radiator hose is soft to touch every morning so no build up of pressure. Jury is still out but I will update at 5k, 10k etc.

After the Blue Devil treatment, I did 4.5k miles with the car. I cheated a bit, I never put the thermostat back in after the treatment and I wired a sensor to turn on the aux fan at 80°C. The car runs fine with no overheating. 4.5k miles is very good result with a crack head. I have access to a #14 head, given by a fellow member here a while back, and I decided to change it out.

Bottomline: Blue Devil can patch a crack head for a while. Would I recommend it as a permanent solution? The answer is No. It is used in the trade to sell car. I would leave it at that.