Too Slow warming up


Old 02-12-03, 02:11 PM
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Too Slow warming up


Can anyone explain to me why Chrysler products take so much longer to warm up than GMs?? It seems that a GM truck with a V8 is warmed up in 10 mins or less on a COLD day, and a Chrysler with a V8 even after 20-30 mins has yet to reach 130 degrees F. Are they using weak thermostats or is it just a poor cooling system design?

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Old 02-12-03, 04:00 PM
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Depends on the year of the vehicles we are discussing. Chrysler's fuel controls have always been second rate to GM's.

GM carburetors such as the Quadrajet are the best out there---Chrysler used Carter and Holley models for years and then finally wised up and bought the Q-jet for the 1985 and up V8's. By then, GM had moved to TBI injection on many trucks (1987) already .

As for modern systems, GM fuel injection is still among the best--many other OEMs (Honda, Isuzu, among others) use GM style injectors in some of their models.
Old 02-13-03, 02:21 PM
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Hey Joe,

I really wasn't referring to warm up quality or fuel system integrity. Basically what I'm asking is why the time frame for the engine to reach operating temperature is so long.

The vehicle I'm working with is a 2001 Dodge B1500 Van with 3.9 v6...There really isn't anything "wrong" with it, the user is just complaining that the temperature drops when it's idling. Like it operates at about 190-195 but drops to 130-140 when idling on a colder day, also you can start it in the morning and let it sit idling for an hour and it never reaches operating temperature until you drive it for a while. This is with the original thermostat and a new Stant Superstat for this application.

Any ideas?

Also, not saying this in a wisea$$ way but don't say warranty to me again because I'm in a fleet service garage and we can't send stuff off to the dealer for days waiting for them to fix it.

Old 02-13-03, 04:33 PM
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Again, Chrysler's fuel systems have been far inferior to GM's over the years. As have most of their computer controls and engine management systems.

Warm up time/quality has everything to do with fuel system & engine management design. My Saturn will fry your tuckus in 2 minutes in the dead of winter, while my Chevy Cavalier takes 10 minutes to do the same thing .

There is a reason why Chrysler farms out their fuel systems to someone and that GM makes and designs their own .

As for the cooling system issue, it could have an air pocket, the thermostat could be defective, the gauge could be bad, etc, etc, etc, etc. You'd have to get into it a bit and verify some things.

For instance, I'll say it again----are there any TSB's on the problem for this vehicle? That is ALWAYS the first place to start, bar none. If you don't, you'll travel a road that someone else has done and paved a path already, capish?

Is the dropping temperature met with reduced heat output?
Old 02-13-03, 06:22 PM
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Hang on a minute while I go start my 99 Ram truck up before I write again, it's the same way, slow to warm up (5.2 V8)

It will take it probably 30 minutes to get to at best 160 degrees, it is -15 degrees F outside right now. I can go get one of the GMC utility trucks here with 5.7L gas and it'll be up to 190 degrees in about 5 minutes outside at the same temp.

Hopefully I won't freeze on the ride home LOL.

There are no TSB's on the issue. There are about a zillion of them though on spark knock, but thats another matter.

Apparently the engine isn't producing enough heat to keep up with what the heater core sucks out of the water when idling is my best guess.

In theory, leaning the fuel mixture and making a timing adjustment might let the engine run a little hotter, but of course that's way beyond my control.

Thanks for the help, I'll throw a new T-stat in it and see if that'll warm me up a little more. I doubt it will though.

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Old 02-13-03, 07:12 PM
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I am no professional mechanic by any means and cannot tell you why Dodge/Chr/Ply products are soooo cold blooded they cannot warm up like GM and Ford products. I can tell you, it is an issue I have experienced with countless Dodge/Chr/Ply products.

Now, being the hick I am, I have found that if you replace the stat with the highest temp stat you can get for this engine AND restrict the airflow thru the radiator (such as placing cardboard in front of it or if you are fancy, buy one of those manufactured grill covers), you will notice a temperature increase during the cold months and can ward off hypothermia while you're driving.

Just remember to remove the cardboard when the temp guage starts reading higher than it should.
Old 02-13-03, 09:04 PM
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Mike: NO!

This is an OBDII vehicle and the thermostat is CRITICAL for proper emission control. The wrong temp stat could fool the coolant sensor and PCM and do some funny things. Only the OEM temperature stat should be used. I suggest a replacement from the dealer---the Stant could have been defective, as could have the original.

Original poster: If after servicing the cooling system, you determine it is OK, you might look to see if the dash gauge is really accurate or not. You should be able to use your scanner to read the coolant temperature through the coolant sensor/PCM. The OEM Chrysler manual should also have the gauge specs and how to test it.

Since this is a fleet account, I would simply purchase the OEM manual and charge the account. Chances are they have more than one of these vehicles. The manual will pay for itself time and time again.

If not, an subscription for 25 bucks annually would be an OK substitute.

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