PDA

View Full Version : 99 K1500 Sub 6.5TD - "ECT/transmission problem solved" *for info*



paradit
05-25-2008, 00:23
Hi Everyone,

I thought I would write this in here, since I couldn't find a single thread in the search engine relating to the problem i WAS experiencing.

Background
Bought my sub in NY state and drove it across the continent to Edmonton, Alberta. besides blowing the alternator the trip was problem free. Averaged about 19mph at 75mph the whole trip (empty). Got home and started the paperwork/inspections. my trusty mechanic for my car was given the task of doing the safety inspection. He added gas during the process.
After I got my truck back from him, it started to exhibit what I called "surging" (but after searching through this forum its not what everyone else here calls surging). What was happening was that at a steady speed, the transmission would slip down a gear, then back up-down-up-down-up........took the truck to the stealership thinking they "knew their stuff".

Dealership Diagnosis
After checking the fuel, they discovered a lot of particulate and generally bad gas. They immediately assumed my problem was related to fuel and recommended replacing all injectors,injector pump, glow plugs, drop and drail fuel tank, flush lines, replace filter..........estimate $6600Cdn. I just paid 7k for the truck so i said i'm going to get a second opinion

GCL Diesel Injection Service - Edmonton
On the recommendation of a friend, dropped the truck off at GCL here in town. They had the truck for about 4 days with lots of phone updates. lots of "tried this, but didn't work, still searching for problem". Then i got the "aha" phone call. Trevor there discovered the problem.

The Culprit
Trevor discovered that the engine temperature sensor (i'm a layman, but a different sensor than the one that drives the coolant temp gauge) was constantly outputting -38C. He said after reading in the books, if the engine thinks its cold, it won't let the engine stay in O/D. And so the engine would go into O/D, then drop back to 3rd gear.
He swapped the $30 part with a new one, also replaced the lift pump as it was only 1.5psi output and the truck is running fine now. Total bill $520.

Epilogue
Monday I visit the stealership to stomp my feet and try and get something for free. Not leaving without.
I did a lot of reading on this great website - thanks to the tech experts who so often post their knowledge freely.

Tyler
Edmonton, AB
99 K1500 Suburban 4L80E (i think) no mods but now reading as to my best choices.

Robyn
05-25-2008, 07:17
Glad you got it fixed

OH first off WELCOME TO TDP :D:):D:):D

There are so many dealership techs that have not a clue about these engines.

You were blessed to find a good mechanic in your area to help.

Actually your tranny was shifting into OD what was not working due to the temp switch was the last shift, The lockup of the converter clutch.

The shift from 3 -4 is very subtle and the lockup is quite noticeable as the RPM drops a lot.

The engine temp has to be about 170F before the ECM will allow the TCC to activate.

This is done for a couple reasons. The fluid in the tranny will be up to temp and the engine will be all done with the cold advance cycle and running smoothly.

Its mostly a drivability issue as I see it.

Again, glad you got it fixed.

You might want to consider a good Racor filter in the fuel system to handle any crud thats in the tank.

You can use the factory filter as a primary and the Racor as the final filter.

The filter needs to be able to handle about 35 GPH of fuel flow to allow the needed flow though that these pumps require.

Best

Robyn

Busted
05-25-2008, 19:36
Welcome to TDP Tyler :D I'm about 30 minutes west of you on the Yellowhead--out in Stony Plain. Nice to see more Albertans joining up!!

Turbo Al
05-26-2008, 11:41
I am "just" over the Rocky bumps in B.C. Thanks for such an informative post.

Welcome aboard

Al

enormiss
03-24-2009, 10:23
I've been researching a shudder that only happens in top gear...
This is an interesting thread, I would have never expected the two to be related.
Since my temp gauge doesnt go much over 160 I guess I'll look into that first.
Thanks to the original poster and others for the info :)

KallyI
03-25-2009, 00:46
Welcome to the forums, good to see another Albertan here!:)