Peter,

That doesn't sound good. I have to check again to make sure, but I believe that one of the times that I went to add coolant I thought that the car was basically cold, but wham, I got hit with full pressure.

__________________
-Mike
'87 300TD 304kmi (RIP)
'95 Toyota Camry Wagon 125kmi

Typical problem with these cars. Usually only a head gasket unless it has been overheated. Mine is using more coolant than I would like, and I have oil in the coolant tank, too. No trouble, even on my trip to Florida, but I still believe I have a head gasket in my near future!

The original head was trouble. The re-design replacement is much better, but not cheap.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

About the Evans coolant stuff - has anyone put that in a Mercedes OM617 or OM60x engine? It sounds fantastic at first, but after reading the fine print on their site I have serious doubts. Water pump modifications? Capacity increase required (to 3-4 gallons)? Possible flow issues? It sounds like they cater to American V-8's, I don't know if they even have a clue about Mercedes diesels. But if it is a drop-in replacement, I'm sure interested!

:-)

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

I guess I'll be weighing in on the "cold pressure in coolant system means bad things" side of this discussion. Read on for further info.

Well things aren't going so well. I went to the parking garage without calling first so that I could see the car cold. First thing was the large amount of coolant under the car. Next was the pressure in the coolant system. Then I released it an confirmed that the pressure builds up promptly upon starting the car. No rough gurgling under acceleration, but quick pressure build up.

So I decided immediately to take it to my mechanic, Nick. They carefully washed the entire engine and inspected it for all the leaks. When the belly pan came off we had all three fluid types in great quantities: engine oil, ATF, and coolant. This was a dramatic change from 2500mi ago when I had the pan off to change oil and had small quantities of ATF and oil.

Now for the bad news. The coolant comes out of the head at a place above the head casket on the rear cylinder (I saw the fresh coolant on the clean head too). Nick says that in his experience this nearly always proves to be a cracked head. The oil leak at the casket and front seal is pretty heavy too. And the transmission seal leak is too bad to ignore any longer. I also have a rear bearing that needs replacing.

My wife and I have decided that we like the car well enough to continue to invest in it.

I'd appreciate any opinions on the following prices. Also anything I should be sure to do while I have the head off?

Labor to remove and replace head and front seal: $1300.
Labor to replace the transmission seal & rear wheel bearing: $500

Nick recommends a new head only. Nick gets his for $1850.

Thanks,

__________________
-Mike
'87 300TD 304kmi (RIP)
'95 Toyota Camry Wagon 125kmi

Hi Mike,

Wow - bummer! Sorry to hear the diagnosis. Yours appears to be in advanced stage of illness, relative to mine. Anyway, I recently called the dealer and was told the front main seal is ~3 hours labor, including removing the radiator. I was told (by a friend) the head gasket is 6-8 hours if done by someone with a clue, otherwise I guess it could be more like 10. My dealer's labor rate for "B" labor is $106/hr. So the labor you quote sounds a tad high, but not ridiculous. (Anyone else care to comment?)

I don't know about the tranny stuff, but if it's the front pump seal, the tranny needs to come out. You may want to replace the pump itself, I've heard that a new seal on the old pump doesn't work well because the shaft wears or something, the proper fix is a new pump (and seal). The pump would tack on another few hundred $$$.


As to what else to change while the head is off, unless they've been done in the last ~5 years or ~50kmi:

1- Injection pump vacuum shutoff valve ($20-30)
2- All 6 glow plugs (~$75-100)
3- Closely inspect the serpentine belt tensioner ass'y ($25-250)
4- Have all 12 valve lifters inspected for wear (~$20 each)
5- Have the timing chain inspected for wear/stretch ($???)


The BenzBin lists the head for $1495, the trans pump for $265, valve lifters for $16/ea, and the timing chain for $62. Rusty will usually at least meet their price, if not beat it - and his service is reportedly superior to BB.

MegaParts has the transmission pump for $235, but their prices were higher on the other stuff.


Good luck, and keep us posted!


Dave M.
Sacramento, CA
1987 300D - 229kmi
1987 300D - 234kmi
1984 300D - 206kmi

Mike:

Sadly, I suspect you mechanic is correct. At the very least, the head needs to be checked carefully. If it has not been replaced, the new head is much more resistant to both warping and cracking.

The coolant and oil leaks are typical of a failed head gasket, too, though, so you may in fact not have a cracked head. It is, though, probably cheaper to replace it than it is to have the work done twice!

The other prices are pretty much what I would expect. The rear wheel bearing is a pain -- seem to remember about $400 to change the one on my TE (previous owner's records).

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Msyoder,

Does the new head come with the valves installed?

The labor cost is very high, sounds like about $100+ per hour. There is no mechanic in the world worth that much an hour to me. Of couse I would do it myself. Where else could I make $100+ per hour tax free? You could too.

I wouldn't replace any glow plugs unless the old ones were bad or the vacuum shut valve. There parts rarely go bad and if they do, they don't prevent the car from running or do any damage. If the cam timing is 3 degrees or more late, then a new timing chain is should be installed and maybe new chain guides..

P E H

GSXR
The only dynamic test that I can suggest to solve your dilemma is to leave sack of tomatoes(Sacramento)and head up 80 to Tahoe.If you have a blown headgasket or cracked head your temp gage will rise toward the red because of the exhaust gasses in the cooling system.
Good luck,
Peter

__________________
Auto Zentral Ltd.

PEH,

Remember - this is an OM603 engine, not an OM617. TOTALLY different animals!There is a specific reason I said to replace the glow plugs and vac shutoff valve. Both jobs are a NIGHTMARE with the intake manifold in place. It takes 5 minutes to R&R the shutoff valve with the manifold off, and 1.5-2.0 hours with it on - BT, DT. Ditto for the glow plugs - they're nearly impossible to access. With the head removed, it is incredibly simple to replace these parts. If they have 5-10 years, or 100k+ miles on them, it's simple preventive maintenance that's well worth the extra $100 part cost, which is negligible considering the job would be $3000 without doing those two things, or ~$3100-$3200 with (assuming a new head is needed.) There's no way I'd leave the old stuff in unless recently replaced! The intake manifold R&R is also several hours (with cleaing it up, etc).

I agree on the timing chain, if stretch is less than 2-3 degress it's probably OK. Changing it as preventive maintenance is a judgment (or budget) call.

The heads come totally bare, except for seats & guides I think. No valves or lifters. The lifters are common failure also, they collapse and "tick". Again, it's easier to have these replaced with everything apart, yanking the camshaft to do them later is not fun...


Best regards,

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Nick says that the heads come bare (no valves or lifters).

I have already done the glow plugs, serp belt tensioner, and fuel pump shut off.

Luckily when a glow plugs started going bad they started with ones that I could change. Can't remember how many I was able to do without taking off the intake manifold, but IMHO it is impossible to do them all. I got the rest done when the manifold came off to do the fuel pump shut off.

I'm going for it -- i.e. I'm in for the head removal labor to see if it's cracked. May know by end of day or tomorrow.

Thanks,

__________________
-Mike
'87 300TD 304kmi (RIP)
'95 Toyota Camry Wagon 125kmi

Now ya'll have got me wondering about my 300D. It is strange. The car runs/drives/starts up great, no problems whatsoever but sometimes when I drive it and let it sit for a day or so I still have pressure in the coolant reservoir which results in a slight leak at the seal for the aux water pump (I am figuring because of the elevated pressure). I am not seeing any oil in the coolant nor white smoke. I do see the slight loss of coolant because of the aux pump. Once the 240D is up and running I may pull the head just for the heck of it to see if there is anything obvious. My narrow minded way of thinking would lead me to believe that if there were a problem then the "pressurized" coolant would eventually wind up in a cylinder somewhere which would cause a whole different type of problem (bent parts). Today when I got home I opened the reservoir cap and relieved the pressure which seemed to be comparable to the amount of pressure that is there after a day or so of cooling off. Funny thing is, during this time, the radiator was hot but the water temperature in the reservoir was not even warm. Also, when I opened the cap the level in the reservoir did not move.

__________________
Jim

It's normal behavior, but I dropped out of the thread because there's no way to prove it to someone used to the American/Japanese coolant systems.

Granted, a real crack can leak combustion gases into the coolant system. If that happens you'll start to see a negative effect on the running temperature.

I'd hate to see someone have a complete head job or even replace their head gasket when their car is behaving normally. If its not overheating, losing coolant, or showing any bubbles in the coolant, drive.



Ken300D

Ah, Ken, Ken, Ken. I'm not as stupid as you (and others) may think! It is not normal if there is HIGH pressure in the system when cold. A little pressure is no big deal, and could even be called normal. 15+ psi is way wrong when cold, period. I don't know why you think American/Japanese cooling systems aubmit to different laws of physics than German (European?) cars do. Try the simple squeeze test on the upper radiator hose with the engine cold. If it can be "twanged" like a guitar string that's not right. It should be soft & squishy. The cars never did this before, so do you mean to imply that zero pressure when cold indicated a *problem* with my cars, when they were running perfectly?

I don't think "engatawork" necessarily has a problem, though - it depends on the amount of pressure being described. I say that because he has an OM617, which are MUCH less prone to this type of failure. The OM603's have a known issue with head gaskets and cracking, 617's don't. I do think it's odd that the liquid in the tank was cool with a hot engine, sounds like possible flow issues? Thermostat? The level not changing doesn't surprise me, it usually won't unless the coolant is quite hot. But, as you say, if there is no coolant loss or overheating it might not be worth investigating.

Remember: Both of my 1987 OM603-engined 300D's, with high pressure when cold, ARE LOSING COOLANT!! Quite rapidly, too - a quart per 400-800 miles.


Regards,

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Jim:

Sounds like your aux circ pump is dying -- it shouldn't leak even at 20 psi hot. A little residual pressure is normal, and a small leak will make it works -- air will get drawn in at the small leak rather than via the radiator cap.

I'm suddenly loosing coolant in the Volvo, which leads to poor milage and drivability problems when the cold start device stays on (no injection timing increase with engine speed). I smelled hot coolant last night, so I think it is time for all now hoses and a change to fresh coolant, along with new glowplugs and a check on the d.....d glow plug relay -- I think the glowplugs aren't heating proplerly.

Dave:

Mysterious coolant loss, especially if accompanied by high coolant pressure cold or oil in the coolant tank is a sign of cracked head or blown head gasket. A blown head gasket will eventually allow enough coolant loss to overheat the head, at which point it will crack. Best to replace gasket before more damage occurs, especially hydrolock!

Mike:

And anyone else faced with a cutoff servo replacement on a 603 -- pull windshield washer reservior, take two Cresent wrenches, and take off the ALDA (hex flats on ALDA and captive nut) -- it tips over toward the engine and rotates out from under manifold. This will give you enough clearance to remove the servo. Total job was less than two hours, next time will be on the order of 30 min. Much faster than removing the intake manifold.

Get a flex socket for the glowplugs, they can also be removed without removing the intake manifold.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter,

So far I haven't had any hint of hydrolock, or other obvious signs of coolant entering the combustion chambers. (knock on wood!) But I agree that I need to get this looked at no later than early spring, when it gets hot here in Sacratomato and the cooling system must be at 100%.

Now, about the ALDA - I've always wondered how hard it is to R&R. What does it connect to inside the I/P? If I wanted to "tweak" it to enrich the mixture a little, I could remove it, turn the screw, and then re-install? It would be nearly impossible to turn the setscrew & locknutwith the ALDA and intake manifold in place!


About the glow plugs, I know then can be done with the manifold and injecotr lines in place, but it sure looks like a multi-hour bugger of a job. Thankfully MB designed an oil leak at the #2 intake runner that develops over many thousands of miles, so when glow plugs are needed often the intake gasket is too. What a convenient coincidence! I'll be doing this on my b-i-l's 1987 300D sometime this month, as a matter of fact... already have the gasket, plugs, and vac servo from Rusty (Atlanta Wholesale Parts, 800-741-5252.)



Thanks again,

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!