1998 Lumina 3.1 rpm jumps at stop

[JimMadsen]

Last night while driving home from work in a thunderstorm and shortly after driving slowly through a huge flooded intersection that was only deep enough to rinse the bottom of the car but not get into anything (pretty sure, maybe only a foot deep), I started to feel rough engine feelings at speed. Feels as if straining a bit. Shifting feels ok going 1st to 4th when it should. I am really not sure if it is supposed to shift higher than 4th. I drove standard for years and I listen to the engine vs watching the tach all that much. So it was the straining sound and rough feel in the pedals that got me paying attention.

 

It does shift and I see the expected 1:1 needle line up for tach and speed and then 4th drops the tach a bit. But going to work this morning when I got up to 70 the engine sounded as if it was in too low of a gear. The needle lead me to suspect it was in 4th. If I was driving standard, the sound would have me shifting into 5th. Then I hit a traffic jam (was actually so bad from an accident, I turned around and went home to try again later this morning!) while in the pretty much stopped, idle forward a car length then stop traffic, I saw that my tach was jumping from 700 to 800 then back down and back and forth. The engine sounds corresponded with the increase / decrease in reported rpms. The engine sounded and felt guttural like something was faintly coughing. The sound was so subtle that anyone else sitting in the car probably wouldn't notice it. I am just so in tune to the cars sounds.

 

I changed the oil about a month or 1000 miles ago with Mobil One 5000 mile oil (still change at 3000 though) and new STP filter. Replaced idle air control valve, alternator, serp belt, harmonic balancer all within past 8 months. Replaced throttle control sensor about a year ago. 3 weeks ago replaced exhaust pipe/resonator and muffler. Got the wrong size cat to resonator gasket from Napa so just put on exhaust sealant which was what was on the old one.

 

Car has 130,000 miles on it and I have owned for 2.5 years. I have not done any tranny work on it, but I have not and still do not feel any slipping. I am of the opinion that if tranny ain't broke, let it be. Too many horror stories of people getting that quick flush that destroyed their tranny (and yup I realize damage was already there and the new clean fluid just removed the gunk that was making tranny feel like it was ok). There are no error code lights and engine temp is right around 150-160 degrees. Only thing really different is that I am using the ac more but it comes out cold. In car volt meter in cig lighter port shows battery at car off at 12.6v and while running 13.8-14.2v.

 

I cannot sink any serious money into this for about 3 weeks, and I can park it for some time if needed. But I am more than willing to go poking around and do some cheap stuff to try and keep it going. I will not be able to replace the car for at least a year, so gotta keep it going.

 

Heck for all I know the engine just got wet and will be fine later.

 

Thanks

[Garrett Powered]

your battery may be good when cold but what about when its hot out and you throw on the ac?

 

 

is your voltage the same when you are using it in the traffic jam? or is the IAC steps choking the alt out and heating it up? possibly the charge wire got hot and stopped putting out good amperage at low rpms.

 

I guess get us a datalog of it operating with the ac on in a traffic jam and the problem will reveal itself. look when the rad fan kicks on and tell us the voltage. when the engine bay is over 100 degrees hotter than normal.

[Garrett Powered]

you should probably drop that pan too. give it a new filter.

[JimMadsen]

your battery may be good when cold but what about when its hot out and you throw on the ac?

 

It really wasn't that hot. Maybe 55 degrees. I just happened to have it on ac and usually have the blower going for air movement. Same thing happened after I turned it off.

 

 

I guess get us a datalog of it operating with the ac on in a traffic jam and the problem will reveal itself. look when the rad fan kicks on and tell us the voltage. when the engine bay is over 100 degrees hotter than normal.

 

Not sure what you mean by datalog. How would I obtain it, or am I just writing voltages down as I try different things?

 

As for the pan, I can probably do that fairly soon. I am not flushing it but just changing it, adding new filter, more magnets, and new gasket. Since I am not flushing it, I should not have to worry about the tranny problems I mentioned before because of the gunk removal, correct?

 

Thanks

[Garrett Powered]

a lot of guys are data logging these days because you can use your laptop and a cheap cable to get all the sensor data to compare with voltage and if you can review it and see what's going on then it becomes clear what to do about it. how old is the lower intake gasket?

 

I agree, don't flush it, just change it and keep an eye out for leaks. unless you get it done with a snap-on tranny service machine which uses the pump in your transmission to move fresh fluid in. rather than forcing the fluid in with a machine that will pump it in and possibly blow out seals. or do it yourself but change that filter first.

[JimMadsen]

So I would want something like this:

http://www.amazon.com/ScanTool-425801-Interface-Diagnostic-Software/dp/B005ZWM0R4/ref=sr_1_19?ie=UTF8&qid=1369494502&sr=8-19&keywords=car+diagnostic+cable

 

Looks good since it would also work on my other car, a 00 Merc Mountaineer plus anything else I get down the road under 15 years old. I can get that shipped and here by Wed. I assume the car should be ok to drive.

 

Was thinking about your voltage questions. The readings I got was while driving with engine at temp with ac both on and off. I had already driven about 10 miles at both highway speeds of 70 and stop and go traffic jam. I used my plug in volt meter which I know is not the best, but it is great for a quick check. I like the idea of the cables data log feature.

 

I have had the car since Oct 2010 and have not changed it myself. I am very new to repairing my cars but have done the repair work in the first post myself. I also have the dealer 98 lumina 3 volume service manuals. But being new to cars, it is pretty overwhelming until I get some proper direction. For instance, I do not know where the tranny pan is (I am sure I can find it easily enough) and not even sure yet what the lower intake gasket looks like! But as I said, learning as I go and getting pretty good at the learning part. Even decent at finishing the work!

[Garrett Powered]

wow, not sure about that cable. does not look anything like tunerpro RT v.5 which is what I use. and Robertisaar cable.

 

I am doing the intake gasket for the first time on a 3400 soon. I actually plan on rebuilding the whole motor now. the tranny pan drop I did on my tgp went pretty smooth but I had an inch/pounds torque wrench for the bolts and the hardest part was getting the seal for the filter out without chipping the aluminum.

 

but the intake gasket I believe can create a range of conditions I'm sure.

[JimMadsen]

I looked at tunerpro and free beats paid every time. Any pointers on the cable? I can get cheap ones for $10 on amazon, but that is worthless if won't work.

 

I do have a torque wrench

 

The gasket replacement starts on page 6-74 in the service manual and only takes a few steps. Seems to be pretty straight forward but I have never gone this deep into a car before. That being said, I am sure it would be at least $500 at a shop to replace a $50 part on rock auto. Worried that it would turn into a all day job and that would have to wait until at least next weekend if not longer.

 

Would be nice to diagnose properly first and then take it from there. It looks to be one of those things that I would also replace the tstat and water pump at same time just cause it will be drained and I am pretty much there anyways. Heck I would much rather wait until my next oil change if I could! But that being said, how would I tell if it actually is leaking? The car only has 130k on it. Is it something where I can just drain a little bit of oil and see how it looks?

 

OK... just figured I would go check a few things before putting this post up. Oil level is fine and do not see anything milky in it. Coolant has some fluid in the res about an inch below the cold fill line. It is brown and has a lot of sediment in it. So obviously I need to change that. I know that I can get a proper pressurized flush for $100. BUT when I had that done on my mountaineer due to no heat, sure enough started leaking something fierce (was not leaking before) and I had to find the leak. After I bought a new water pump it turned out to be a small pinhole leak in one of the hoses coming off the pump, but replaced that and the pump and tstat since why not. So $250 later all told, and still no heat I finally flushed the core with water and its working great. I calm myself by saying she has 160k on her and probably needed to be replaced anyways!

 

So I am thinking of changing, not flushing the fluid and should I replace the tstat and pump at same time just because? My heat works fine btw. The engine sounds like it has with a lifter clicking sound. I have learned that while this is not ideal to leave it alone, it is normal enough in the 3.1 to investigate later and the oil levels are fine. My old mazda made this sound when it was time for an oil change! Better than the light or stickers.

 

Currently after the car sitting since Fri am, the rpm in park is at 1000, in drive but not moving moves up to say 1025 and goes up a little more when ac is on. When engine just started from cold, putting out 14.2 volts. So maybe I can ignore this for a bit (yeah I know, dangerous) get that cable, hook it up and get some readings to see whats happening.

 

Sorry for long convoluted post, going to take car for drive this evening and will post again.

Thanks

[Garrett Powered]

if the coolant is brown that is whats wrong with my 3400. bad LIMG. you need the metal one. common GM thing on the 3100/3400

 

http://www.w-body.com/showthread.php/51487-OBD1-ALDL-Cables

 

 

I understand you can get OBD2 plugs put on these.

[Garrett Powered]

but its for OBD1.5 cars or something. you need HP tuners?

 

or upgrade to OBD1

[JimMadsen]

I posted in the other thread as well. Looks like OBD1 to usb cables are much harder to come across. He appears to be out of them so I will keep an eye on that thread.

 

Is the 98 lumina a obd1 or obd2? Or am I completely clueless on this one? I thought it was all a standard port under the steering column that you go to autozone to check your codes at. As well as make changes, but I thought it was standard (sorry complete noob about most things cars)

 

Is this thing ok to put off a few weeks until I have time and $ to replace everything? I am seeing that I will have to:

 

coolant drain

oil drain

replace lower gasket (am I near the upper so should replace as well anyways)

probably should replace water pump and tstat at same time since it is drained and I am right there anyways

and at some point change tranny fluid just because I should along with dropping the pan, new filter and few extra magnets added in

 

I have only had a few minutes today to glance at the service manual to see that the job shouldn't be too hard, after all under the hood and on top should not have too many rusted bolts! But if I can delay this some it would really be beneficial. I do commute 17 miles each way m-f. I do realize anything you say comes with no guarantee about worthiness of the engine.

 

thanks

[Garrett Powered]

yeah you wanna keep driving it that much, keep up on the maintenance for sure. motor and tranny

[AL]

Your 98 is OBDII

[JimMadsen]

Thanks Al, will get my amazon find cable.

 

I think on the coolant, I am going to drain it first and refill it without any pressure just in case it is brown because of rust and debris from 130k and 15 years. After that, will start looking for signs of a leaking LIMG. Hate to tear into the engine if I do not have to.

 

Then I will do the tranny change and pan drop.

 

Simple first complex later. Any signs I should be looking for that would get me better diagnosing leaks before and after coolant change?

[JimMadsen]

DEAD CAR!!!!!

So car seemed to be doing better until the drive home today. Engine felt as if it was working too hard and the temp gauge was a tad outside its norm but still under half. The weather here is getting to be pretty humid and we are supposed to get a heat wave next week.

 

The more I looked into it the more I think coolant is just old dirty and rusty but needing a change. I am concerned about one huge thing. As I was reading through the service manual I saw something about not mixing the green coolant if the factory dex coolant is in there. I may have done that when I added some extra coolant I had after doing wifes water pump. I did not and do not know what was in the system as the coolant predates my ownership. The oil is still clear and the exhaust is still coming out clear.

 

But now I am even more wanting a coolant change and willing to get a flush now to get any possible sludge out if I did mix the two. I would then deal with any post flush problems.

 

I pulled into a monro where I get some work done and talk to the guy there. He agrees with my thinking and said it does not look like I have any head gasket or LIMG problems yet (he did nothing except bs with me for a few, no looking at the car) and said he would not do the flush since he is not equipped for problems with those.

 

So I drive it to the service station down road from my house where I usually get my gas. I was on E anyways. I park it and walk to the service door but they are already closed for the day. Go back to the car and it will start then idle to zero immediate and die. Try again, same thing. Wait a few minutes and check battery level and oil. Both fine. Try again and now not even starting.

 

Figure maybe gas was lower than I thought and needs some but I go by mileage and my gauge. I should have at least another 15 miles I can drive. But what the heck, put in 5 gallons just to see what happens. I can start the car and then press down on the gas. As long as I keep RPMs over 1000 car runs. Take foot off the gas and car dies.

 

I am thinking 2 things primarily. First (hopefully the correct one) it is vapor locked after I drove through that puddle and humidity is up. Too much water got into the system and it just needs to sit over night. Second would be a bad sensor that got wet and finally went.

 

Either way, it is parked at the service station and in the morning I will have them try and start it. If it runs, have them do coolant. If not, figure out why. Diagnostic charge would be around 100 so thats worth it to me!

 

Any other thoughts?

 

I am betting a Torque Converter Clutch failure after reading some more. Looks like it is inside the tranny so I can get a new filter and some extra magnets put in at same time. Please let me know if I am going down the wrong path before I start talking to station in the morning. I do not want them taking my wallet for a ride on this.

Edited May 30, 2013 by JimMadsen

[JimMadsen]

Car started fine for them this morning and they let it idle for 45 min without a stall. I went down and talked to the mechanic and gave him the full background on the issue.

 

They test drove it and we settled on maybe I had some water in the tank and the new gas and the sit overnight took care of that. Lame but sounds good. I told them to go ahead and change the coolant, they looked at the color and said looks like really old dex cool. They checked for a head gasket leak (not a LIMG, but I can just watch the oil and coolant) and found nothing. When they backed the car out of the bay, it stalled. Now that they believe me they looked some more.

 

The IAC spring was coming away from the plastic so they screwed that back on (it is under warranty from autozone so I am going to bring it in) and heavy heavy heavy carbon build up in throttle body. They offered to clean that out for an extra 60 on top of the coolant change.

 

Being 90 degrees and humid today, I did not want to run the risk of driving the thing home and then doing it myself for first time. So I had them go at it. Got the car back and drove it around, will see how it goes in the am for my commute.

 

Tranny fluid change still in the plans, probably at end of summer. Not feeling anything slip and no thuds switching gears right now.

 

Thanks all for the help