Cooling and Idle problems

[blackhawk60]

This week I have noticed that after start-up and during the first few miles(5-10) of driving, my h2o temp will rise up to the "N" and then drop down and stay down. Each start-up there after, the temp has raised a half of a letter higher. So now (Fri) the temp went up to the "O" and eventually it dropped down.

Yesterday night, I started up when leaving work and let the car warm up approx 5-min as usual and noticed that when I step on the gas the engine wants to "dip" down to 500 or so rpm, almost dying. I added some oil because it was low but it did the same thing this morning. Are these two problems related.

I have a new t-stat and radiator in the car, both less the 5k miles.

<small>[ November 01, 2002, 12:04 PM: Message edited by: blackhawk60 ]</small>

 

[ckinart]

i had a similar problem not too long ago with my coolant temperature fluctuating... it would come up at a normal rate for a bit, then it would jump up to the "O" or "N" in "NORMAL" for a minute or two, and then would suddenly drop right back down to a regular temperature... turned out that i had air in my coolant system following an upper rad hose replacement... i don't know if that's your problem, but it's a real easy fix if it is... when the engine is cold, take the rad cap off, start the car and put your heat to full... then let it idle for about 20 - 30 minutes, keeping an eye on the coolant level... it will likely surge up and down, and when the t-stat opens, it will *hopefully* puke up some bubbles... try squeezing the upper rad hose now and then while doing this... like i said, may not be the problem, but it's a real easy thing to try...

as for the attempted stalling when you give it gas, i would first suggest resetting the idle program, and then if that doesn't help, consider cleaning the IAB valve...

good luck...

 

[twr]

blackhawk60:
This week I have noticed that after start-up and during the first few miles(5-10) of driving, my h2o temp will rise up to the "N" and then drop down after a couple of miles. Each start-up there after, the temp would raise a half of a letter higher. So now (Fri) the temp went up to the "O" and eventually dropped down.

Yesterday night, I started up when leaving work and let the car warm up approx 5-min as usual and noticed that when I step on the gas the engine wants to "dip" down to 500 or so rpm, almost dying. I added some oil because it was low but it did the same thing this morning. Are these two problems related.

I have a new t-stat and radiator in the car, both less the 5k miles.

First problem certainly sound like a sticking thermostat. What T-Stat did you use, Motorcraft??

Second item could be a number of things. TPS, MAF Fuel pressure just to name a few.

I don't think the 2 are related.

 

[blackhawk60]

Well I do think that there is air in my system, however I did not use a motorcraft t-stat, it was from autozone. As for the other problem. My fuel pump is brand new as well and after a few miles it doesn't drop anymore. But its the time it takes to "warm" up. I don't know why the engine does that but I did have stutter problems in the summer also. All my plug wells are sealed and have new plugs and wires, the IAB is clean too. Maybe I'll kick the Alero out of the garage and start putting the SHO in for the winter.

 

[blackhawk60]

ckinart
as for the attempted stalling when you give it gas, i would first suggest resetting the idle program, and then if that doesn't help, consider cleaning the IAB valve...

good luck...[/QB]

How do you reset the idle program?

 

[rangerj]

Blackhawk60,

Any air in your system from the change of thermostat and radiator would have been "burped" out through the overflow a long time ago (the first day).

After putting 5K on the engine since the new radiator and thermostat without this problem, the problem is a new one.

The "new" thermostat may not be opening at the right temperature. If you are getting air in the system that is causing hot spots, where is the air coming from? Is there a head gasket problem, or a poor radiator cap?

Are you loosing any antifreeze? Again a head gasket problem could allow antifreeze to be taken into the cyliners. Does your exhaust smell like anti freeze, or is it a thicker white smoke but not as thick as oil smoke?

You may want to do a compression test, and/or get the test kit to test for exaust gas in your coolant.

Letting the engine run without the radiator cap, and watching for air bubbles, when the coolant changes over as the t-stat opens, is also a good idea. If you get foam or a lot of bubbles, this is another sign of a head gasket problem.

The first thing I would recommend is that you put an OEM thermostat in. Make sure that the air relief valve (jiggle valve) is "up". If this does not solve the temperature problem, then start looking for a more serious problem.

If you are getting coolant in the cylinder(s) it could cause your stumbling problem, so the two problems could be related.

The wild temperature swings you are getting are not NORMAL (no pun intended - well maybe just a little). You are right to be concerned. Now start by doing some diagnostics.

As for the Alero being put out of the garage, if it is "her" car, we will see who wins that one!
Good luck and hope this helps, rangerj

 

[blackhawk60]

There was some loss of antifreeze when I noticed a small hole in the upper tube the day after I installed the radiator. I finally recieved the tube but haven't had a chance to replace it yet. In the meantime I coated the pinhole with some liquid tape and wrapped it with duct tape. there is no leak at the moment. I haven't noticed a difference in my exhaust, it seems pretty normal. The t-stat is about 5k mi old. The radiator is <1k mi old.

And as for the Alero, I own both, so I call the shots.

<small>[ November 01, 2002, 11:56 AM: Message edited by: blackhawk60 ]</small>

 

[blackhawk60]

Newsflash: I am still leaking coolant. That's probably the reason for the temp swings. Looks like I will be putting the new hose on tonight. I will let you all know what happens. Thanks for the support.

 

[rangerj]

Blackhawk,

If the source of your coolant leak is a pinhole, this could be the cause of your temperature spikes. You could be sucking in air as the engine cools down.

While the engine is hot and the system is under pressure you leak a little fluid. Then when it cools down the fluid contracts and the void creats a vacuum. This is how the overflow bottle system works.

Once you get the leak repaired let us know if things go back to normal. rangerj

 

[blackhawk60]

Yep, those two problems seem to have been related. After replacing the hose and adding the coolant that I had lost, the car is back to normal. I still don't understand why after replacing my radiator and cleaning the low coolant sensor that my light never came on when it was low. And I am still wondering why the rpm's dipped down before the engine got warm also.

 

[rangerj]

Check for any codes. If there are no codes you may want to put it on a scanner and moniter each sensor in real time, that is while it is running.

Pay particular attention to the O2 sensors, the idle air control, the temperature sensor, throttle position sensor, and MAF. Any one of these could be operating on the edge of the perameters expected by the computer.

If none of these are the obvious culprit, then try running some injector cleaner through the system and clean the throttle plate. Consider the above as just some food for thought! rangerj

 

[blackhawk60]

But the thing is, I don't have any of those symptoms anymore. Only when I was low on coolant. My O2 sensors are brand new. The throttle plate is clean, my injectors probably need a cleaning, the maf sensor(s) are clean, the ECT is new, and my TPS is new. There is two other problems that may have something to do with my slight power loss and stutter when cold. I know one of my cats is partially clogged and there is also an exhaust leak at the y-pipe ******. So until I fix those.....

 

[SHOZ123]

It may be the timing is being change due to the swings in engine temp. AFAIK the IAT and ECT working series to give the PCM temp data which the timing is based on. When the temp data is low the timing is advanced. You may be in the area where the timing is being ********, hence the lugging or drop in rpm upon accelerating.

You may just be noticing this because of the cooler air temps affecting this temp data to the PCM.

<small>[ November 06, 2002, 02:54 PM: Message edited by: SHOZ123 ]</small>