2002 LS, Coolant/Performance Issues

[dmgrizz]

I've been driving a 2002 Chevy Impala LS since my dad passed it down to me with about 60K miles. It ran well until about 70K - which is when I began experiencing some performance issues. Automatic transmission shifts would lag a bit/trouble shifting down. I took it in and they said the catalytic converter was clogged which was replaced. I'm now at 95K miles and on my way to take it in for service (ironicly) and the check engine light came on. I told the service center and when I got back they found nothing and had reset the light and changed the oil etc.

That same day I drove from Nashville to Knoxville and halfway there the check engine light came on. A few minutes later I began intermittently getting a low coolant warning but the temp stayed within normal range - no real fluctuations. When I got to Knoxville I had noticed some performance issues similar to the old ones revolving around the transmission. I checked the coolant reservoir and noticed is was a little low so I filled it up. On the way back I continued to get the low coolant warning, check engine light, and performance issues but no temperature problems. After the trip I found no coolant leaks at all despite indicators.

Any ideas? I realize there been some issues with the DEX coolant but I would assume my radiator had been flushed at some point and DEX wouldn't have been used as a replacement. Could I have a small coolant leak into the engine block somewhere? Or is the converter clogged again and the coolant light just a fluke?

Thanks!

[Scrapper]

have you changed your coolant sensor? and no on the block if any crack or anything i'd say hedcasket do a compression check if you can and plugs should tell you something the way there burning when you take them out you may try check oil see if it looks milky on dipstick.

[HeMi101]

Catlytic would have nothing to do wit coolant light. Now for performance issues yes. Find out what code is coming on (why your getting the check engine light) Some place like Autozone should scan it for free. That will help.
I Had a Clogged Cat, and I lost all performance, only got a code for "Multiple Misfire Condition" after pushing it a little too hard. I'd bog right out and 4K RPM and It wouldn't up-shift at all. But I've never seen a bad cat cause down shifting problems, but can't say its not possible.

The transmissions Taking long to shift, and problems down shifting could be the transmission it self could still be due to age at this point. Just do a quick check of the fluid for color and Smell (see if it smells burnt), seeing your nearing the 100K mile mark, These trannies can get pretty crankly around this millage, its worth checking anyways.. I know mines on its way out at 93K miles, lagging on shifts (Slipping) and Problems with up and down shifting, and P1811 with Very harsh shifts.

If you take care of dexcool properly there's really no problems with it. Check what color it is, if its Green its regular coolant, if its orange its dexcool. check to see if theres any gumming up around the Radioator cap, could be time for a flush if it hasn't been done. Could be a fualty coolant level sensor, or Could actualyl be leaking, and if its the original LIM Gasket, I'd probably say check around there.

[dmgrizz]

It ended up being an external leak. There was crack in the carbon fiber elbow near the engine belt. Coolant was coming out and running down the side of the engine block but fortunately not going in. This coolant was DEX so when I get the elbow replaced I'll flush the fluid and use the green stuff. I would agree with the age issue. It's probably time to have a transmission fluid flush as well as replace some of the spark plugs and maybe look at the fuel system for cleaning too.

[HeMi101]

Doesn't really make a difference what coolant you use, as long as you maintain it, Dexcool will give you good service with no problems. Only problem I have with it is GM advertising it as "100,000 mile life", still needs to be flushed sooner than that. And I totally forgot about the elbows on the 3800. Theres 2 of them, and they can be a P.I.T.A.

heres what they pesky buggers look like.


Regarding possibly tuning it up, Your right at that point it's a good idea.
I'd seafoam it, then do new plugs and wires (Stick with ALDELCO Plugs cuz the engine can get cranky about em), and change the fuel filter.

At this age, It'd be better to do a good ol' Pan drop instead of a true flush for the transmission. Could disturb dirt thats happily stuck in little corners, that can cause leaks and blockages.

[dmgrizz]

I just wish I could have the performance I enjoyed during the early years

She used to be able to "get up and go" but now I drive with caution in mind at all times :

I'm heading to the local dealership this week to get this part replaced. I'm sure the part is cheap but labor will be outrageous. Unfortunately, I'm on a college campus so I don't have the time, space, or resources to fix it myself. I'll head home soon and tune the ol' baby up. New spark plugs, clean it up as much as possible...maybe even treat the front end to a nice steam clean

[HeMi101]

Should do your self a 0-60mpg before and after. mine was 11 seconds before, and now back down to 7 seconds after my tune up.

[dmgrizz]

Update:

I got the elbow replaced, there ended up being 2 with a total product cost of about $40. However, labor cost me a good $250

I'm still experiencing "bucking" like I used to get back when the catalytic converter was clogged. I ran a check on the engine light and it came back code P0102. This is an input problem with the Mass Air Flow (MAF) Sensor. I'd like to get in there and clean it after seeing other similar posts involving the same problem. Many of them claimed to see incredible performance improvements afterwards. Admittedly, I'm not sure where this sensor is. Anyone know?

Thanks for all the help!

[Schrade]

Originally Posted by dmgrizz

Update:

I got the elbow replaced, there ended up being 2 with a total product cost of about $40. However, labor cost me a good $250

I'm still experiencing "bucking" like I used to get back when the catalytic converter was clogged. I ran a check on the engine light and it came back code P0102. This is an input problem with the Mass Air Flow (MAF) Sensor. I'd like to get in there and clean it after seeing other similar posts involving the same problem. Many of them claimed to see incredible performance improvements afterwards. Admittedly, I'm not sure where this sensor is. Anyone know?

Thanks for all the help!

MAF sensor is somewhere on the air intake.

The other mechanic said they found nothing, and you had a light??? Don't go back, except to get your $$$. Even if the light goes out, it stays in the computer as a Hcode History.

Dexcool will give you good service with no problems

Gotta' raise the flag on that one heme01...

I got the 'plug', on 4 Dex vehicles, out of 4 Dex vehicles owned. Including a pedigreed 1-ton '02, bought new maintained immaculately. At 20 months, it had the 'plug'. Stayed running all 20 months too - 195kmiles.

Dexsux better than Shop-vac.

[Scrapper]

have you found the maf yet? if not the hose leading to air filter it's not at that end it's where the other end of black hose but it should be on top of where it goes on the moter should look like a little square box.

[HeMi101]

MAF is on the Throttle Body, farthest from the intake side of it. Black rectangle with wires coming off it, can't miss it.

[Gems]

It's just in front of the throttle body... Requires a torx screwdriver to remove the 2 torx screws holding it in place... Be sure to clean it using MAF cleaner or electrical contact cleaner... DO NOT use throttle body cleaner to clean the MAF...