Hello again, it's now heating up outside here in the "Great White North" and I've noticed that my coolant temperature is rising slightly higher than normal.

I had this problem last year, and a repair of my radiator and changing of hoses didn't help. I will go in to a pro this time for my rad flush as I have been doing it myself for the last two years.

I was just wondering if removing the A/C from in front of the rad will help. It currently doesn't work and the compressor was removed, all that remains is a hose conncted to the grill that sits in front of my rad. I'm guessing more air flow to the rad might do the trick.

The temperature, when it goes up, doesn't really rise significantly ( goes closer to 175 than to just in between 175 and the last notch on the gauge) so I figure it's something minor like that.

Please help.

Thanks,

AARON ROCHARD

1976 230.4 W115

Isn't 175 pretty normal??

After I replaced the cylinder head on my 250/8 the temp now is usually around or a little above 175 whereas before is was more like 200 all the time. The cooling passages in the old head where really corroded. For some reason the fan for the AC system no longer turns on automatically when the 212 temp switch on the water system turns on so I wired a switch to turn it on manually under the dash.

I think you are okay but you could try adding water wetter to the cooling mixture and lessen the amount of anti freeze you ahve in the system. If you aren't in an area where it's cold enough to freeze then you don't need so much anti-freeze anyway... make it 60% water instead of 50%.

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MB 72 250 M130.923 114.011 170k The Beauty

Thanks, I will try adding more water, however, not too much as I live in Toronto and it gets pretty chilly up here in winter.

I did have my head gasket go on me near the end of last summer (in an uncommon spot in the middle of the engine block) so I'm a bit concerned about temperatures going up. I do believe it may have happened, though, due to the rad repair shop I took it to. Hard to prove...

If you say 175 is fine, that should be O.K. I just wasn't sure if the engine temperature should raise up at all, even when it warms up outside.

Thanks,

AARON ROCHARD

1976 230.4 W115

175 may even be a little cool. I believe about 190-200 is where most engines normally operate for maximum fuel efficiency and power.

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

Thank you so much dieseldiehard. You've explained a lot to me here.

First of all I may have been the person that contributed to the head failure, because I had been flushing the rad by simply emptying the rad, adding and changing my flushing solution/coolant and then bleeding the system through the water choke until it reacts normally. I never allowed the temperature to reach higher than 200, but nevertheless, I know now what to look out for.

As for the coolant issue, I had been using the regular Prestone antifreeze, but it says on the back of the bottle that it is safe for aluminum heads. I take it that you disagree with this...

I had been currently using the 89C thermostat because of my (or what I thought was) running slightly hot, so I can see if the 71C is available the next time I change it. It might help my car heat up faster in winter as well. It does get really hot up here in summer, (and obviously pretty cold in winter, so It sometimes gets difficult to make the car all seasonal.

I believe the rad should already be grounded, however, with years of use, the ground could be rusted out. I'll give a look-see.


Thanks again,

Aaron Rochard

1976 230.4 W115 4 cyl. Gasoline

Another possibility is dirt in the radiator fins. Take your garden hose and nozzel and squirt water from the backside of the radiator.

Another problem may be a buildup of deposits inside the radiator. Take it out and have it professionally cleaned at a radiator shop.

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Regards

Warren

Currently 1965 220Sb, 2002 FORD Crown Vic Police Interceptor

Had 1965 220SEb, 1967 230S, 280SE 4.5, 300SE (W126), 420SEL

ENTER > = (HP RPN)

Not part of the in-crowd since 1952.

175F is the normal operating temp for a 76 -- any lower and you either have the wrong thermostat or it bad and not closing properly.

The corrosion problem with aluminmun heads (not an issue on the diesel, it's cast iron) is lack of adequate anticorrosion additives in the coolant. They get "used up" so you need to change the coolant every two years.

"Green" antifreeze doesn't provide the same level of corrosion protection as the "orange" stuff (GM Dexcool compatible), but the orange stuff still needs to be replaced often. Prestone antifreeze, in years past, was claimed to be safe for use in aluminum/cast iron engines, but in fact, most manufactures would not honor warrenties if it was used -- no corrosion protection AT ALL, holes would appear in the head in 20,000 miles or less!

MB coolant is the way to go, but if you wish to use aftermarket antifreeze, use low or no phosphate orange coolant and use distilled water to mix it.

Peter

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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!