PeachParts Mercedes-Benz Forum - View Single Post - 1987 300TDT cranks but doesn't start and other fuel system questions

swogee · #13 05-31-2005, 07:05 PM

Thanks for all of the good posts so far.

I have had the 1987 300TDT for about 1 year now, but I figure that I have only put maybe a 1000 miles on it since I bought it. I have been running Mobil 1 Truck and SUV (aka Delvac 1) for only about 650 miles or so. When I first got the 300TDT I noticed it made a metallic knocking sound that was not the usual diesel knock. More recently before I changed the fuel filter I noticed a tapping noise at idle that has been fairly consistent. After getting the 300TDT started today, I listened for the tapping noise and it seemed to be coming from under the valve cover. In order to rule out the injectors I think I will drive the vehicle for a few hundred more miles and see if things quiet down. I did a search on lifter replacement, and I think the procedure according to GSXR is to warm the engine up, pull the valve cover and then press on on the lifters one by one. If they squish down, then they are bad. I would rather not replace the lifters, so I will give it some time and see what happens.

As for the fuel heater/thermostat, I guess I will need to investigate the parts further. Since the whole fuel heater assembly is bypassed, I have no idea what is bad and what works. I was hoping any heat exchanger/thermostat failures would be something obvious since I don't feel like hooking it back up and taking a chance.

-Steve