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Discussion Starter #1
any thoughts whether the 2.2 liter engine design makes for a slow warm up in the winter?

my gas mileage has really declined this winter, and i've noticed that the engine takes a significantly longer time to warm up, compared to a couple of other cars in the family.

i've changed the thermostat a few times in the last few months (super stant and OEM, both 195*), but it doesn't seem to improve the warm up times.

the lousy gas mileage could be due to a number of things...the cold weather, winter gasoline, air conditioning automatically turns on when air vents directed at windshield, more city/less highway driving, etc..... but i'm wondering if the engine design (slow warm up time) is a contributing factor.

thanks
 

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If the thermostat is good, and the manifold pre-heater is working (the tube from exhaust manifold to air cleaner) along with the flapper valve, then typically it will reach operating temperature within about 3 miles when it's about 20F or so. As much as 4 miles if sub-zero, and about 2 to 2 1/2 miles if about 40F or warmer.

How many miles does it take for you? Turning on the heat or defroster before it reaches the warm mark will delay warmup more.
 

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You could have air trapped in the system.Did you use the recommended cooling system filling procedure of raising the front end of the car when filling the coolant ? I've also found the repeatedly squeezing the upper rad. hose when the rad. coolant is right to the top of the neck also helps to burp more air out of the system. You need to keep burping and filling until no more air bubbles are released and the coolant it right at the top of the neck. Then install the rad cap and fill the overflow bottle to the proper level.
 

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I have always had slow warm up with my 2.5. Like you, I have tried different thermostats. The OEM has worked best for me. The engine still takes a looong time to warm up and I have accepted the fact that these cooling systems are not an example of fine engineering. I have done the burping as well. The only time I get the warm up times as Bob has mentioned is with much warmer outside temperatures when the heater is not needed.. I would also welcome suggestions too.
 

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Discussion Starter #5
thanks for the comments.

i got up this morning, and tested my 1989 reliant against my wife's 2002 protege5. the reliant took 10.0 kilometers(6.2 miles) to reach operating temperature, and the protege took 2.1 kilometers (1.3 miles)

same temperature ( -13*C/ 8*F). same driving conditions (quiet rural road, no traffic, at about 65 kph/40mph). same 1 minute warm up in the driveway. the heating system set to full heat/defrost, with a/c on.

last november i installed the Super Stant tstat using the burping method (method #2), and last week i installed the OEM using the air bleed plug (method #1), as described here:

http://www.allpar.com/fix/radiator-purge.html

the OEM shop manual suggests that chrysler deliberately used a tstat with no air vent on the 2.2 and 2.5 to provide a faster warm up ('...this provides better heater performance', p 7-16)

i'll check if the manifold preheater is working. might install a block heater too. thanks again
 

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Even at 8F, I get a warmup of about 3 miles, maybe 3.5. It was a little longer with a cheap thermostat. But 6 miles is unacceptable and is NOT normal for this engine. My wife's Toyota 4-cyl would warm up in 1.5 miles on the coldest day, so Chrysler products (including the slant-6 and older V-6s and V-8s) always have been worse, but not this bad.

Make sure the heat stove has not rotted away from the exhaust manifold; that the paper tube is secure at both ends; and that the flapper is pulled closed on a cold start. Not uncommon for the flapper to fail by the brittle plastic vacuum line to the thermostat breaking off, or the thermostat failing (it's that disc with foam on it inside the air filter in the housing).
 

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When it gets this cold, help the little engine out and block half the radiator with a piece of cardboard to allow more time for the fluid to warm up. Blocking half the radiator is not going to do any harm and I have done this for about 20 years when I am in the cold 35 degree and below areas.
 

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Yes, that works, but again, 6 miles is just too long a warmup period even at that temperature. Should be between 3 and 4 miles in the coldest weather. Something is not working properly, and it's best to find it rather than compensate.
 

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Have to agree with Bob on this one. Something is amiss. Even on a subfreezing morning all my vehicles are almost to operating temperature by the time I get 2.5 - 3.5 miles away from my home. I usually have at least warm air from the vents (if not totally hot) before that. I do keep the fan on low until the air temp is at least "warm" unless I need to defrost a heavy frost or ice.

Unless there was a problem with the cooling system even my old Acclaims were almost to operating temperature - even when they had over 200K miles.

The only time I remember a vehicle never producing at least warm air was in subzero temps back when I lived in CO (early 80's). We were getting low temps of -40 F to -20 F with highs of -10 F to -15 F for a week at a time. I still shiver when I think about those days. You know it's too cold when the moisture exhaled freezes on your mustache! It was heatwave when the temp reached 32 F........
 

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It's extremely easy to disconnect the vacuum line at the airbox that powers the heated air flap and forget to put it back, at least on my Spirit. The vacuum leak is insignificant enough that it isn't noticeable, but the heated air flap won't have any vacuum to its servo and will default to the open position (full cold air).
I like to run the heater blower on low for the first few minutes. This keeps the heater core in the circuit, and gives you a very little bit of warm air. Keep in mind that the heater core on these cars is a full-flow core and that a heater core is a small radiator. So running the heater forces ALL your coolant through a small radiator that has a fan constantly blowing cold air across it.
 

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Keep in mind that on your 89 vehicle, the radiator cooling fans will run anytime you are using the defrost (AC compressor running). Forcing 8 degree air across the radiator is not helping matters. As soon as the thermostat opens you are circulating and mixing in some pretty cold fluid. Your newer model cars probably don't do this (even my 96 mini-van will not operate the cooling fans on a very cold day with the defrost on). So... you are loosing some efficiency there. I know you have to defog and de-ice the windshield; you just can't get around that. That little bit of inefficiency was engineered out in the mid 90's and later vehicles.
 

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B10alia said:
I like to run the heater blower on low for the first few minutes. This keeps the heater core in the circuit, and gives you a very little bit of warm air. Keep in mind that the heater core on these cars is a full-flow core and that a heater core is a small radiator. So running the heater forces ALL your coolant through a small radiator that has a fan constantly blowing cold air across it.
This isn't accurate at all. The heater core is ALWAYS in the circuit for your car, whether the fan is on or not, and no matter what position the climate control is in. And it's not true that ALL of your coolant goes through the heater core. The flow comes out the thermostat housing and splits - part goes through the top radiator hose to be cooled, and part goes to the intake manifold to heat it, then to the heater core, and back to the water pump.

However, in early K-cars, there is a water control valve, or heater control valve, which is vacuum-operated. Its purpose is to block flow to the heater core if A/C is selected, so it can cool more efficiently. If it's stuck in the close position, the car will experience poor or no heat. That valve was eliminated c1990 - it was gone from Daytonas by 1992. None of this, however, affects how quickly the engine warms up.
 

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Sorry a bit O.T.
So does this mean for my 89 LeBaron that, when I've removed my A/C compressor and still if I select "A/C on" from the auto climate control, I get a bit colder air to the cabin?
Bob Lincoln said:
...However, in early K-cars, there is a water control valve, or heater control valve, which is vacuum-operated. Its purpose is to block flow to the heater core if A/C is selected, so it can cool more efficiently. ..
 

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If you have a water valve and it's in working condition, selecting A/C will block the heater core flow. It won't actively cool the air, but it will prevent some heat flow into the airbox, so the vent air should be a little cooler. How much you'll notice - doubtful that you'll really feel it.
 

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If the thermostat is totally closed (i.e. for the first few minutes after startup), the only fluid that is moving is that which goes through the heater core. Once the T-Stat opens, the fluid flow splits, with a higher percentage going through the radiator.

Also, for the older cars with a heater control bypass valve, the only time fluid goes through the bypass is when the recirc position is selected on the panel. The AC can be running with outside air selected and in that position coolant is not being bypassed but goes right through the heater core.
 

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Right - I should have said that "Max A/C" blocks off the heater core. Some cars have that label rather than "Recirc", but it's the same function.

And during warmup, the flow through the heater core is unaffected by whether the heat is selected or not - still pumps through the core.


Bottom line, something is wrong with a car that takes 6 miles to warm up.
 

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Thanks for that correction, Bob, I guess I got bad info. Someone told me that the core was a full flow core that cut in and out of the circuit when the heat was turned on or off.
I still think, however, that the problem could very well be the vacuum line to the airbox. If you take the airbox off, in my experience, that connector just pops loose, and putting it back on is always one of those little things that skips my mind.

I would not recommend a block heater. From the research I've done, the only ones that heat the engine (relatively) evenly and safely have to be installed through a freeze plug, which is certainly more work than it's worth. Heating pads, heated dipsticks, inline heaters, etc., all seem to be more hassle for very little reward, have little temperature control and are a fire hazard, don't actually warm the engine block itself, warm it unevenly... the list goes on.
 

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Yes, that rigid plastic line to the air cleaner's thermostat can snap off easily, or someone can forget to hook it up after an air cleaner is re-installed. That will disable the flapper valve and therefore any pre-heated air. I had the thermostat fail once, and scavenged it off a spare air cleaner, as parts stores don't have them. But even without the pre-heated air, it should not take 6 miles.
 

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Granted it's a different vehicle with a different engine, but I made some observations on my way to work in my Ram. From a cold start (ambient temp 27 F) the temp gauge on my Ram was at about 1/3 and I had moderate heat by the time I had gone 3.5 miles. In another 1.5 miles the engine was at normal operating temp - on the Ram the gauge is just under half - and the heat is hot!

But even in my old Acclaims they had "heat" by the time I had gone 3-4 miles and were at normal operating temperature at 5 miles.

If you're over 6 miles and low heat, something ain't kosher - even if the flap is inoperative.
 

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I can confirm that on my 91 Spirit, with the morning temperatures at 50 to 55, heat set to high, selector set to panel (i.e. dashboard vents), blower set to 1 or 2, it takes about 1-1/4 to 1-1/2 miles before my hands feel warm air out the vents. It may take a bit longer if I'm defrosting, but then the air is directed at the windshield and chilled a little :). By 4-5 miles the temperature gauge is near normal and I'm getting full heat from the heater. My gas mileage definitely suffers, even in our temperate Winter mornings here in FL. My commute is only 8-9 miles so the car only has about 4 miles at a fully warmed up condition. You can definitely see it on the Traveler. At about 5 miles from cold it goes from the low 20's (MPG) to 28-33 in a matter of 30 seconds.
 
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