'85TD... Coolant High Temp & Pressure...

I do not have a coolant pressure tester and its late... so, i'll get a loaner from autozone tomorrow.

I removed the thermostat to perform these tests (tests performed with water only)...

I do have a MightyVac... vac side works great pressure side leaks.

I put 15Hg vac on the coolant system and it held for 15 min.

I can blow about 5psi into the pressure side with my mouth... I put it on the cooling system and started the car and it got up to 5psi after a couple of minutes... but would go no higher as the MightyVac pressure side leaks.

There do not appear to be any leaks.
The oil is typical black (not brownish and/or thinish)
there was some smoke... but, I adjusted the ALDA and now there is none.

Removing the cap @ 80C pressure *seems* typical... but, at high temp there is high pressure

Loosening the cap when the temp begins to rise... allows the coolant to boil/blow out rapidly as temp/pressure rise

After about 20 minutes of running time it heats up rapidly (whether in town or on the road).

Radiator is OE about seven (7) years old... aux fan works... coolant G-05

Water Pump????

opinions please

thanks

dennis

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'84 300D (211k) *New*... (Wife's)
'85 300TD (174K) 10th Year... (Mine)
'96 F-350 7.3L Dually (149K) Since New
'85 300D (156K) ~~~Wrecked~~~ Damn it! (parts)
'84 300D (176k) ~~~Wrecked~~~ Damn it! (parts)

Is there a problem you're trying to fix? What temps do you run in normal driving?

I modify all my car T stats,I drill a hole or more if I can't find a cooler stat.Most cars run just to hot for my liking.My diesel stays at 78C unless climbing a mountain,it will see about 82.I use a electric fan for city traffic.As a engine ages it will get scale and rust stuck to it.The only way to clean would be full tear down an rebuild.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

Lots of "data" but not much meaningful. The only temperature you state explicitly is 80C. What is "high temperature"? You state coolant is G-05 but then state tests performed with water.

Without anything else to go on I'd say do a citrus flush, replace your thermostatand water pump, refill with anti-freeze and hope it's not a blown head gasket. If it's not fixed with that, then start giving details.

We really need baseline data and then problem data with an operational profile to even attempt a diagnosis.

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Current Stable

• 380SL (diesel)
• Corvette C5
• Manx
• Baja Bug
• F350 Powerstroke
• Auburn Boattail Speedster replica

I do not speak very well... my apologies.

The car overheats to 120C within 15-20 minutes. The car normally runs @ 80C-85C.
Once it overheated... I removed the thermostat and used water to try and diagnose the problem.

again, my apologies.

__________________
'84 300D (211k) *New*... (Wife's)
'85 300TD (174K) 10th Year... (Mine)
'96 F-350 7.3L Dually (149K) Since New
'85 300D (156K) ~~~Wrecked~~~ Damn it! (parts)
'84 300D (176k) ~~~Wrecked~~~ Damn it! (parts)

Does the overheating occur sitting in traffic, on the highway, or both?

__________________
Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Auto part stores also sell super coolant additive drops the coolant level about 20Dgs or so they say, most likely your pump is bad if you took your Thermostat out and it still over heats
while your in there's it would be smart to do a flush and the change fan clutch.

Pressure tested today... damn head gasket... removed head (block/head fine)... put on hold... ordered new timing chain and rails while I'm @ it.
Thanks to my wife xoxo (see sig below) I have plenty of spare parts... so, I went ahead and swapped the radiator, water pump and fan clutch.

rock on

__________________
'84 300D (211k) *New*... (Wife's)
'85 300TD (174K) 10th Year... (Mine)
'96 F-350 7.3L Dually (149K) Since New
'85 300D (156K) ~~~Wrecked~~~ Damn it! (parts)
'84 300D (176k) ~~~Wrecked~~~ Damn it! (parts)