You said that you replaced the intake gaskets. If it's running hot now, I would suspect a vacuum leak. thinner fuel/air mixture the hotter it burns.

Could be that valve timing is off as well.

I did run it rather rich to test that theory, same results. I wired the aux fans to be on full time, that has helped. But on extended trips, it still warms up to just over 100c, but never more than that.

Pump came today. Not to others, if you buy Laso (one of a couple OEM brands) they come with main gasket, temp housing gasket and t-stat o-ring. While those are cheap, now have three of each. lol

pull the radiator and do a reverse flush for 5 - 10 minutes. I just replaced my radiator because mine has partial blockage for a while and I never noticed it. my car would get up to 100C if it was just sitting ,, but now it it can sit for a while before the needle even moves. also check the fins on the radiator and also make sure none of the passages are pinched.

Not sure if running it rich is a legit test. I've heard of the smoke test, where you blow smoke into a vacuum line and look for some coming out somewhere.
I've also heard to test for a vacuum leak, spray ether (starting fluid) around suspected leaks and listen for an increase in RPM. But be very very careful as ether is extremely flammable.

There are only so many things that make a car run hot. From the sound of it, the car ran at proper temp before the intake gasket change, but not after.

A cooling system should not sludge up overnight to that extent. I would look over the original work, double check vacuum lines and what they hook up to.
Look at the MAS (the round thing that moves up and down as the accelerator pedal is depressed) it should be closed at idle, if it's open just a tiny bit too much air will get in.

good luck

I will check again for intake leaks. Would the car really run super smooth on such a lean mixture? I still have enough power to make some nice g-forces :) And it idles super smooth. Fuel economy, which I check with EVERY gas up and have for years now is at 18mpg. 20 on highway trips if I behave with the throttle. Again, those numbers are still the same. And I agree, it is odd things were fine before and now not. Something changed, obviously.

Nonetheless I will do a more thorough check and check the deflection plate again.

I hope to replace the pump this weekend. If anything, that will be the culprit or then ruled out.

As for back-flushing the radiator, did that when I did the last garden hose flush. All together probably ran over 100 gallons through it, if not more.

Re: Air Flow Sensor Plate ("MAS")
1) The plate is not connected mechanically to the throttle linkage or accelerator pedal, and therefore does not move mechanically with movement of the pedal.
2) The plate does move in response to changes in intake air flow. When the actual throttle (down, almost out of sight at front of engine) is opened, increasing air flow will cause the Sensor Plate to be pulled down, which in turn raises the fuel metering plunger, causing more fuel to flow.
3) If the Sensor Plate is pushed down by hand while the engine is running, the fuel metering plunger will be raised, making the mixture richer, not leaner!!

Good info. Either way the plate is fully closed as it should be at idle.

Numerous vac leak tests with starting fluid produced no results. In fact, like I said earlier, if anything they may be less leaks (if there is one now). The brake booster line to the lower manifold was not tight at all. I even now notice a difference in breaking since fixing that. Also the intake gaskets are sealed with gasket sealer. So in theory, they should be spot on sealed.

Was going to do the pump tonight, but it looks like the balancer has to come off? Did not plan on that. Anything else I should know??? :) I think the balancer is straight forward. I will mark it.

Probably Sunday, maybe tomorrow night if I have time, I will replace and report back. Honestly, I am not expecting it to resolve the issue. Gut feeling. But at least I can rule it out.

Thanks for all the input thus far.

I don't think you need to remove balancer, there might be one or two spots with indentations on the balancer where you can access the water pump bolts. But then I never worked on a 5.6. Other benz's I have seen that.

I will see if there are, that would help. I did not look very close. Either way, I bet I push this project off another week. :(

Garage has a 750il parked in it and that is not moving. Temps here are over 80 and very humid. Not the best weather for car work in the open, but this has to get done.

Check the vacuum to your ignition distributor, if you have not done so yet. I suspect some misplaced vacuum hoses.

Your car not getting enough air that explains your car is running hot. Try redo the job, check the intake valve from air filter to throttle body. Check everything even the sensors.

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I dont think that is right. If I was not getting enough air I would by default getting too much fuel, and the car would run cooler.

You are full of awesome! Maybe I would have spotted them before I yanked it all apart, but I doubt it. I saw one (maybe there is only one) of those notches! That will speed things back up and make it an hour project again instead of two or more. MUCH appreciated!

As for vacuum lines. I traced them all and they are all correct. The only change I made was to pull the vacuum line at the intake for the air injection system. But that system has been disabled for years. I pulled the belt shortly after getting the car.

So I then checked vacuum at each hose. A the advance I had plenty of vacuum and when reconnected the car would surge for a half a second. So unless the advance portion itself is bad, that seems to work.

The only odd thing I found was that vacuum from the TB is very weak. But I do not know if this is normal. Via finger tip, I could not feel any vacuum at the two lines from the side of the TB. The larger hose, for purge system, has some noticeable vacuum - but again, it was weak. This was with the engine at a warm start.

The TB vacuum is ported vacuum.

The idea being to suck in fumes from the purge canister only when under load.

Take a look at the diagram below and tell me if i got the right one?

http://www.auto-parts.spb.ru/cat/cat...96abbca6a5d8ee

You now, too much vacuum to the distributor would yield to much advance, which would cause hot running.