'01 SL1, 1.9L 144K-high idle, other strange symptoms

[kaph]

We have a 2001 SL1 1.9L with 144K that we bought in August. We are the second owner. In October we replaced the ECTS because it overheated once and was idling between 2-3K in neutral and park. It seemed to lessen the problem. Now it is idling at about 1900rpms in park and neutral (but not all the time). The rpms are also surging when accelerating at low speeds and in the last couple of days has started "shuddering"(my husbands description) when accelerating on the highway. I would say it feels like it is going to stall and I let off of the gas and it recovers-it did this yesterday when I was going about 60 and accelerating into a high wind. The SES light came on the other night, but when the car was started the next day didn't come on and has been off since. We scanned the car and it came up with the code P0105- I know this is a MAP Sensor, but it could be something else, right? We took it to the dealership to try and get a definitive diagnosis, but they can't seem to tell us exactly what is going on. Of course it didn't do the shuddering thing when they drove it. They are saying they can replace the MAP sensor or it could be plugs and wires. I am frustrated at the fact that this is just a guess. Can any of you offer me any advice from your experience? Thanks.

[OldNuc]

There are 3 things that come to mind. Is the MAP port into the manifold clean and clear? Is the throttle body clean? What does the temperature gauge read when the car is being driven at 30 to 40 mph with the heater off?

When you have a high idle event try this. Turn off the car and restart it, do not touch the throttle. Does it start back up at the proper idle RPM? If so that could be either the MAP or the TPS. Check and clean out the throttle body and MAP port before doing this test.

[metsu962]

It almost sounds like you have two problems here. You still have the saturn high idle problem but you get "shuddering" and near stall-outs as well?

I have the same common idle problem as you do but nothing about stuttering. I have tried resetting the computer and checking for air leaks for my idle and have not found those to be the problem. I'm guessing its a gunked up Idle Air Control valve which may be the same for you.

Unfortunately there are a number of things that could explain the shuddering like sensors map/o2, filters, spark plugs, fuel pressure, fuel pump itself, etc. Hopefully someone else on this forum had similar problems with that and can tell you what it is likely to be.

[kaph]

The dealer is now saying it is the Air Intake manifold. They said they sprayed a fuel mixture on it and it sputtered and stalled. Does this sound like it could solve it? They also said it's going to be almost $400 to fix it because they need to take out the engine or part of it or something in order to replace it.

[OldNuc]

Its a intake manifold gasket leak. Its a common problem with the 01 Saturn. You can remove and replace the intake yourself. There are several posts with pictures and directions on how to do it. I do not have a link but maybe one of the posters who have done it will provide the link. Or, search in S-Series and How-To Library with the search function. Its about a 4 hour job the first time you do it.

You have to fix the problems as you find them. If the intake is leaking then you have to fix that to see if there are other underlying problems.

[rc1488]

Originally Posted by kaph

We have a 2001 SL1 1.9L with 144K ...replaced the ECTS... Now it is idling at about 1900rpms in park and neutral (but not all the time).

Bad Intake Manifold Gasket. Replace it. Ive written a how-to with pictures in this section of the forum. 15 bucks at rockauto.com. Done in a saturday afternoon.

[1995sl1sohc]

The intake manifold gasket leak would definately explain what your car has been doing. Fix this before throwing any other parts at it, the gasket is like $12 plus your labor. It is definately a DIY job, if you have the patience and tools.

[kaph]

Thank you for your responses. My problem now is that we live in Michigan and don't have a garage to use to do the work. It's about 20 degrees out today, so we are probably going to have to pay to have it done, but at least I have the confidence now that they are doing the right work!

Thanks for the help.

[OldNuc]

Once the vacuum leak is removed you might find a couple of other items that are weak. Those can be done outside fast enough that you will not freeze.

[1995sl1sohc]

Where abouts in Michigan are you?

[kaph]

O.K. What types of things should I be thinking about then?

[OldNuc]

Best thing to do is get rid of the vacuum leak and see what happens. Usually this solves most of the problems. If not then the new symptoms will be important to allow a decent diagnosis (big word for guess). The next thing that can cause some of the same symptoms only not as severe are the ECTS and/or the thermostat.

[kaph]

We are in Burton, near Grand Blanc/ Flint.

The strange rpm surges and drops seem to be gone, but the high rpms(about 2000) when in park or neutral after being driven awhile are still there. Could that be a thermostat issue? We replaced the ECTS about 6 weeks ago-the old one didn't look bad when we got it out, but we replaced it anyway.

[OldNuc]

That sounds like a vacuum leak. Did you get the manifold gasket replaced?

[kaph]

Yes, it was replaced today and the high RPMs still exist in park and neutral.

[1995sl1sohc]

Oh ok I am in the Grand Rapids area, thought I'd offer my garage and help if we lived closer.

What is the reading on your temperature gauge? It should read about 3/8 when it's warmed up all the way, if it reads 1/4 you need a thermostat. Also, did you replace the ECTS connector, or check it for corrosion? A corroded connector can give you the same symptom as a bad ECTS.

[OldNuc]

Yep, this is where to start, with the engine temperature. Who did the manifold gasket replacement? That idle RPM sounds just like a vacuum leak. It would not be the first time that something got missed.

[kaph]

Thanks for the thought 1995sl1sohc-wish we lived closer!

We had the Saturn dealer do the work. They replaced intake gasket manifold. The high idle is still there, but the other things seem to be fixed. I will check the temperature gauge. I think the connector on the ECTS looked o.k., but maybe I will check that again too. Another thread talked about cleaning the TB and IAC? Any thoughts on that?

[OldNuc]

Yes, check the How-To Library on the procedure to clean the throttle body and IAC. The link to the videos are in the first post and there are 3 of them. Its not hard but you can foul things up if you are not aware of the pit falls.

When you start the car and let it idle where does the temperature gauge end up? Also when driving at 30 to 40 mph with the heater off?

I wonder if the dealer got all of the vacuum lines back where they belong? Brake booster off of the back of the manifold is a good one.

[kaph]

O.K. When warm the guage reads just a little above a quarter and when driving with the heat off it is exactly the same.

I will check out the how-to-library before cleaning anything out.