My Cat Lives Again!

[lakesidepark]

Details: 1997 Catera purchased April 2006 with 122,000 miles. I have done a lot of work to it, some when I bought it, another round in December, and the grand finale now as the car was off the road for months since February. I just finished my test run of all the work with a long drive in 90+ heat. THe drive made me smile and moved the XM up to the top of the list for necessary repairs thank god it all worked! Its at 140,000 and should be ready for another 60K before any more major stuff needed. (finacee says it seems 60K is the magic number for rebuilding the car... )

This car is a love / hate thing. Lots of maintenance, and a lot of recovery if it wasn't kept up with, and anything simple on other cars is a pain on the Cat. But tell me where you can get a car this cheap with the ride it has. My back and bum knees been waiting for this day for months I love driving this thing.

I thought I'd put a short summary of repairs and improvements (with some fubars!) over the last year:

1) Transmission - it crapped out in the first week. Yeah, shoulda known when I drove it. $2800.00 for complete rebuild. This is the only repair I farmed out. The tranny was toasted from overheat, probably low fluid. Recommendations are to get that level checked frequently and address any leaks immediately. Sealed unit my a..

2) Cooling system - Lots of improvements here. I thought the Cat was always supposed to run at 3/4 gauge and cycle the fans! A lot of people here think that too it seems. Today after the hot run I took I will most affirmatively disagree.
Items replaced: 2) electric pumps - one had failed, 1) mechanical pump (the old-style with the new-styled bearings and seal - better cast impeller than the stamped-steel of the new style) as part of timing kit, 1) radiator - was leaking, 1) HCV 1) coolant temp sensor 1) external oil cooler with 180 degree bypass thermostat connected to existing ports (old cooler and lines removed), thermostat and housing (need M8 / 30mm bolts to replace the old 20mm bolts), all clamps.
Items serviced - system flush with old oil cooler removed (it was not leaking but from what I read it needs to go), intake flushed separately, hoses and heater core flushed separately. Refilled with 30% Dex-cool and 70% distilled water with a bottle of Red-Line Water Wetter added. Condenser was removed and blown out - and it was full of crap I don't know how anyone would clean it with it in the car. Took me hi-pressure air to blow the fins clean. Removing all those parts revealed a lot of debris that got sucked in and stuck in the corners of the fans - once again don't know how anyone would remove it without disassembly.
Improvement - All except the final work (radiator and full flush) had been done last winter, but the car still ran at 3/4 on a hot day. However the oil cooler when first installed without a thermostat made it really hard to warm up on a cold day. The cooler did improve hot runs, and probably kept me from burning this car up on hot days while I was figuring out all the other issues.
Today, the thermostat cycled the temp between half and 9/16 (halfway to the next mark on the gauge), and the fans cycled only after a fast run to a dead stop in traffic. Never cycled again after coming on once even if idling for 15 minutes in traffic. MUCH improvement.
FYI I choose Dex-Cool as a preference, it is good stuff IF there is no leaks or contamination. The 30% mixture was more intentional, anti-freeze (the green or the red stuff) is not as effective at heat transfer than pure water (.74 to 1.0). Of course you need the corrosion protection and the lubrication, but unless your car is exposed to -20 for a duration its too much if you use more. And the Cat needs all the help it can get to cool without the fans kicking in. The Red-Line is compatible with the Dex-Cool and improves the heat transfer above the level of pure water, and it also has corrosion protection and lubrication. So far the results are really good.

Engine - replaced all the intake gaskets, cleaned breather tubes, intake, plenum, fuel injectors, IAC, replaced timing belt / tensioner and aux belt / tensioner, spark plugs and wires.
Improvements - the cleaning and gaskets stopped all the leaks and nailed the idle dead- on and 400RPM. The timing belt / tensioner replacement seemed to 'improve'? I didn't gauge the timing before the change but I know it was exact when I finished, and I think it was off before (or maybe I'm just glad she purrs and growls!). Oil PSI runs at 31 at idle and hits over 60 by 2000 RPM. And, finally....no leaks. At least not yet.

Diffferential - This is a fubar. I saw the leaks and thought they were from all the other stuff I was planning to fix, pinion seal was leaking and it ran dry. Toasted the pinion. Replaced the differential. Lesson - sealed unit my a.... check the level and fix any leaking seals and don't wait till 140K to do it.

Steering / drivetrain - flushed and sealed the power steering unit, replaced tie rods and idler, front and rear pads (rotors are still good wow) and new 120+ rated Eagles. Control arm bushings front and real look good, driveaxles look good. The ride is what it is for those that have ridden in them rolling good.

AC unit - replaced compressor - this is another fubar - the aux belt tensioner failed and ripped under the clutch and after that it was leaking out the shaft. Oh well, lesson is that if you know its bad don't wait to replace it, and this Cat is NOT forgiving on delayed maintenance.

Money spent - too much. But all the repairs I did were less than the one transmission repair, if you can't do them yourself then this car is way expensive.

I'll be here a while. I'll keep posted on the temp improvements since these are the biggest problems everyone is seeing to solve this time of year, but my lesson is that you have to look at everything, all the parts, even the clogging of the fans and coils if you are chasing a temp problem. I'll be running it hard the next two months so I will know.

[lakesidepark]

Wanted to add - when I cleaned out the debris between the condenser fan and the aux fans, I found a tube that directs cooling air to the alternator. Oh yeah, it was packed with leaves. Guess that gotta help that alternator in the hot weather.

[lakesidepark]

End of day 4 on the road again with the Cat, turned in 550 miles today for reimbursement and set off again for another 500 miles.

Took my boss with me. He took the first trip with me last year, his first week there and my first drive with the Cat. It smoked out the cam covers, ran hot, the AC didn't work, the radio (FM only) cutting out, and it had bad tires and foggy headlights. He was not impressed with my new car at all. It was only 86 outside and it was miserable in the hot Cat. Guess I must be a good employee since its been a year and he is willing to try it again. What a difference a year and some hard work makes.

Today, 250 miles at 80mph with temps outside at 97 degrees on Kentucky roads...coolant gauge cycled the same as Sunday (1/2 to 9/16), the first stage of fan would cycle very briefly. Never heard the second stage at all , and I know its there I tested it Sunday Ride is all smiles. No funny noises. And hot as hell outside, we started with AC set to 60...then 65...then he turned his to 75...then 78....I finally turned my side up to 73 so he wouldn't freeze.

I have also read many posts about the battery charging and the voltage getting low in a lot of our Cats. I had the same issues. I bought but did not replace any cables - I did inspect and continuity-test them and make sure all were good. Before, my voltage commonly dropped to 13 in daylight cruise (causing the multifunction module to shut the radio off), and with all on at idle (lights, AC, wipers) down almost to the red zone. With NO changes except cooling system, voltage remains consistent 13.6, with a drop to 13.5 when the first-stage fan kicks in (with AC, and even parking lights). Full load idle never made it below 13.2. What did I learn? Bad cooling hits the charging system with a double-whammy, it adds more load by calling in all the pumps and fans, and it cooks the alternator that needs cool air coming thru the vent tube when it is working double duty.

The only issue? The cassette adaptor for the XM got hot after 200 miles and the player ejected it. Had to let it cool off. But...I had the backup 6-disc CD changer loaded and ready and that thumb had it playing before the adaptor came out and the evil music kept playing

Anyone know where to get an adaptor for the CD changer input that accepts RCA audio line input? Yeah, yeah I know, I'll go check the audio forum.

Props to the info I've gotten here by going thru the posts. I am now confident that my Cat is cooling and running like a Cat should. My recommendations for those that are seeing cooling problems in older Cats:

1) Pull loose the condensor. I recommend removing the condensor (yeah that means AC evac and recharge). After 120,000 miles it is bound to be stuffed. I used hi-pressure air to blow between all the fins, then repeated with hi-pressure car wash. You will see that it gets real dirty and packed in two circles that are behind the front fans. I found a corner pile of leaves and debris in both fans that got sucked in from driving. You won't see any of it if they don't come apart.

2) Radiator - I replaced mine. It had a small leak on the driver's side that I never located. It could have been the fan temp switch but since I already bought it it was going.
At a minimum it needs to be inspected. If not replaced I recommend the same as for the condensor above to make sure all the air that can will pass thru. I do suspect the radiator had clogging issues in the lower portion as my experience has been 140K is usually the life of them unless kept absolutely clean.

3) Fans - I found no problems except the dirt that they pulled into the fins of the condensor and radiator. Test them using the coolant test pins to make sure they all function.

4) Water Pump (all of them) - make sure they work. There is the aux pump (on radiator - runs when temp is above 205 and engine is shut off with the aux fan to cool the radiator - I will recheck this, I don't have my factory service manual with me). The heater aux pump runs when engine is on (quick note - if this pump fails, and if you are lucky, the wire for the pump has a foot extender coiled under the battery...temp rescue is to unplug the aux pump and power it with the heater pump connector - this will help some until that pump is replaced - learned that one last summer). The mechanical water pump is plenty covered in the timing belt threads (you DO take care of that belt right? Get that pump too). Mine had the new-style pump from the recall done before I bought it. But it has a stamped impeller. The old-style had a cast impeller but the seals were crap and the bearings were smaller. I found a third version on rockauto that has the new seals with larger beaings and uses the cast impeller. The cast impeller is a little more efficient and I think the Cats need all the help if the goal is to keep it cool enough to stay off the fans.

5) Oil Cooler - remove the exchanger and go external. Already covered in many threads. It needs a 180 'bypass' thermostat to insure it won't run too cold.

6) Coolant - When you inspect that thermostat and that mechanical water pump and remove that cooler, flush like hell with everything apart. I can't see how to effectively flush without pulling it apart, there are too many paths or coolant, not a simple 'go this way and come back the other way'. I did it with the engine valley exposed so I could make sure it was all clear. Contamination is the enemy to all the cooling parts, and double for the Dex-Cool users (the main issue I could find with Dex-Cool is what happens to it if it gets contaminated or mixed with green stuff - clean system and distilled water mix is essential to prevent the narrow passages of the aluminum radiator from getting clogged).
Run NO MORE than 30% coolant, and use distilled water (No mineral content to clog tubes or contaminate the anti-freeze - contaminents cause sediment to flake out of the anti-freeze). That is plenty of protection, if not you are probably not worried about cooling problems as that is -20 degrees. That covers all in the US and a lot of Canada. Anti-freeze is to lubricate and prevent freeze-up. It is NOT as evvective as plain water for heat transfer, so more than you need is a waste and may even be harm.
Try some Red-Line Water Wetter if you wanna. Since I haven't tested the good Cat with and without I can't say for sure if it has helped with the improvement. Doesn't seem to hurt. It is compatible with Dex-Cool and is even red The purpose is to raise the heat transfer of water.

Coolant gauge observations:
I 'think' the gauge range is 160 to 240 with 200 at the center 'halfway' point. This agrees with the fan action and the normal operating temps in the manuals (remember that a 198 degree thermostat is regulating the temp of INCOMING coolant and the gauge sensor is measuring it on the output side at the coolant crossover; fans operate on the return flow that is close to the temp seen by the gauge sensor). This means: normal operation should maintain between 200 and 205 degrees; first fan comes on when gauge rises beyond the point between the half and 5/8 mark 205 degree; second stage comes on after gauge passes 5/8 mark at 210 degrees; all fans on full speed after gauge rises between 5/8 and 3/4 (215 degrees). This leaves a large gap before you get coolant warning and hit the red zone (7/8, 235 degrees). However, if gauge rises to 3/4 (220 degrees) you already have an issue. The cooling system cannot drop the temp at this point. Fans are all running and all pumps are on and there is nothing more your Cat can do to drop the temp so if its still headed up at 5/8 and does not stop before 3/4 it's time to do something.

I am not an engineer; I just pretend to be one so I can stay in the Holiday Inn a lot...