300SDL Shakeout Run - PeachParts Mercedes-Benz Forum

mplafleur · #1 05-12-2009, 08:53 AM

I took the 300SDL out on an extended run yesterday. (to work and back).

It drives like a dream. Much smoother, quieter, and more comfortable than the 300SD. Also much more power.

The things I noticed that need fixing are:

1) B1 brake piston cover is leaking. I ordered a new seal from the dealer ($3.28).

2) I get great quantities of heat from the climate control. Only when I turn the wheel all the way to the cold end where it clicks do I not get hot air.

3) No air conditioning. Clutch does not engage.

4) Low oil pressure. Hot idle can be less than 1 bar, 0.7 to 0.8.

5) Brake light is on. The parking brake is hanging down a bit and won't return all the way to the top.

The coolant temp was excellent. 85 to 90 degrees all the way. I was looking at the gauge and thinking this when I pulled off into the exit lane when I was arriving home. I made the loop and when I made the right hand turn onto the main street 1/4 mile from home, I noticed my coolant temp was 110.

6) The coolant temp was 115 when I turned if off in the driveway.

I opened the hood and noticed that I was loosing fluid somewhere. It ended up being the lower connection to the expansion tank. I had not put the clamp up far enough the neck. I reclamped it and filled the tank when the engine had cooled down some. I also had the fill up the upper hose of the radiator. I did this with hot water.

Testing after this was interesting. Engine temp was at 100. It dipped back down to 90, then rose to 100 again. This is all at idle.

I paid close attention to the hose and radiator temperatures. It took a whilw for the upper hose to get hot. The radiator was hottest only where the upper hose connected. As the engine ran, the radiator slowly got hotter toward the passenger side. When I shut it off because the coolant temp was now over 100 and visably rising, the left half of the radiator was still cool to the touch. I don't think I had any flow through the radiator.

Thermostat went bad?

Water pump went bad?

fruitcakesa · #2 05-12-2009, 08:58 AM

Quote:

Originally Posted by mplafleur

I took the 300SDL out on an extended run yesterday. (to work and back).

It drives like a dream. Much smoother, quieter, and more comfortable than the 300SD. Also much more power.

The things I noticed that need fixing are:

1) B1 brake piston cover is leaking. I ordered a new seal from the dealer ($3.28).

2) I get great quantities of heat from the climate control. Only when I turn the wheel all the way to the cold end where it clicks do I not get hot air.

3) No air conditioning. Clutch does not engage.

4) Low oil pressure. Hot idle can be less than 1 bar, 0.7 to 0.8.

5) Brake light is on. The parking brake is hanging down a bit and won't return all the way to the top.

The coolant temp was excellent. 85 to 90 degrees all the way. I was looking at the gauge and thinking this when I pulled off into the exit lane when I was arriving home. I made the loop and when I made the right hand turn onto the main street 1/4 mile from home, I noticed my coolant temp was 110.

6) The coolant temp was 115 when I turned if off in the driveway.

I opened the hood and noticed that I was loosing fluid somewhere. It ended up being the lower connection to the expansion tank. I had not put the clamp up far enough the neck. I reclamped it and filled the tank when the engine had cooled down some. I also had the fill up the upper hose of the radiator. I did this with hot water.

Testing after this was interesting. Engine temp was at 100. It dipped back down to 90, then rose to 100 again. This is all at idle.

I paid close attention to the hose and radiator temperatures. It took a whilw for the upper hose to get hot. The radiator was hottest only where the upper hose connected. As the engine ran, the radiator slowly got hotter toward the passenger side. When I shut it off because the coolant temp was now over 100 and visably rising, the left half of the radiator was still cool to the touch. I don't think I had any flow through the radiator.

Thermostat went bad?

Water pump went bad?

Air in the cooling system not bled out?

mplafleur · #3 05-12-2009, 10:20 AM

Quote:

Originally Posted by fruitcakesa

Air in the cooling system not bled out?

There might be air in there now, but I don't think there was air in their before. Something else was root cause of this overheat event. The cooling system had been running great for all kinds of testing, about 70 miles of it on highway and 10 miles of local roads.

If there is air in the system, where is it and how do you get it out?

pawoSD · #4 05-12-2009, 10:24 AM

Are you sure the low oil pressure isn't just a bad sender? Is the sender new?

mplafleur · #5 05-12-2009, 02:07 PM

I've installed 2 sensors and a mechanical basically agreed.

awsrock · #6 05-12-2009, 02:18 PM

I think the owner's manual says that oil pressure can go as low as .3 bar on hot days. I've seen mine go down to .8ish before...kind of scary, but it doesn't do it very often.

mplafleur · #7 05-12-2009, 02:20 PM

Quote:

Originally Posted by awsrock

I think the owner's manual says that oil pressure can go as low as .3 bar on hot days. I've seen mine go down to .8ish before...kind of scary, but it doesn't do it very often.

Yes, it does say 0.3 bar.

But I think I may run 20w-50 and see if I can get a bump. My break-in oil is 10w-30.

pawoSD · #8 05-12-2009, 02:36 PM

Is that normal for a newly rebuilt engine? I've never seen any of our diesels run below 1.5 bar or so, even on super hot days.....

mplafleur · #9 05-12-2009, 03:48 PM

No, but I think that the crank must have been machined a tad on the small size.

I could have plastigauged the journal clearances when I put in the oil pump, but I wasn't going to remove the crank and have it done to second oversize even if it had come out bad. I'll live with it for a while.

pawoSD · #10 05-12-2009, 04:03 PM

Isn't that going to case a problem with the piston cooling oil jets? I thought they only open above .5 bar pressure?

mplafleur · #11 05-12-2009, 05:41 PM

Quote:

Originally Posted by pawoSD

Isn't that going to case a problem with the piston cooling oil jets? I thought they only open above .5 bar pressure?

I don't think they need the spray at idle, and anything above idle above 1 bar.

I was thinking of bumping up my idle a hundred rpm by changing the ELR position.

Hit Man X · #12 05-12-2009, 09:09 PM

When I went to heavier oil in my 300sel (5/30 to 20/50) I picked up around 0.5bar of hot oil pressure.

FWIW

pawoSD · #13 05-12-2009, 11:10 PM

Quote:

Originally Posted by Hit Man X

When I went to heavier oil in my 300sel (5/30 to 20/50) I picked up around 0.5bar of hot oil pressure.

FWIW

I picked up about .3 bar in my gasser by going from Mobil 1 0w40 to 5w40 synthetic diesel oil.....it seems quieter too. The M103's like the heavy stuff!

mplafleur · #14 05-13-2009, 08:36 AM

It looks like that's what I'll be doing.

I also have a radiator coolant flow tool I'll hook up tonight to see when the thermostat is opening and if the pump is circulating any coolant.

mplafleur · #15 06-21-2009, 11:33 PM

Thermostat was fine, as well as water pump. At least to spec. My problem was evidently the loose connection at the coolant reservoir. I'm firmly stuck at 82*C now.

However, I believe these cars have a water pump that delivers far less flow than needed.