Towing with Chevy 6.5 TD

[j54mark]

As I have mentioned more than once, my tow vehicle is a '94 Chevrolet K1500 6.5 turbo diesel with 3.74 gearing. In response to a thread started by someone about something, I made passing reference to a recent trip to Colorado/New Mexico and my dissatisfaction of the truck's towing capacity while in the mountains.

I need to explain.

It turns out I had a vacuum leak, as well as problems with the controler for the fuel pump. The mechanic says my wastegate was just staying wide open, giving me no boost, and the fuel mixture was mostly lousy anyway.

So, the bottom line is, I have no idea how one in proper tune can cope with towing at high altitude. For all I know, I could have passed everybody on the road. Ok, I do know better than that.

Mark

[Ken J]

I just sold my 6.5 turbo diesel Suburban a few months ago - I live at 6500 feet. It was a great truck except when it came to hills - it would heat up - never over heat but it would get pretty hot. Did all kinds of stuff to try to fix it with no success. Since there are lots of "hills" around here I sold it and got the 8.1 - what a difference - its a rocket.

Ken J.

[j54mark]

I've not had any overheating problems. The highest I have seen is 235, and that was on a hot day pulling the trailer up a good seven percent grade. It slowly climbed up to 235 and never went any higher. Even with the ac on at highway speeds it never goes over 185.

I understand the overheating issue on these diesels is not uncommon, but not universal either.

Mark

[Ken J]

This was the first vehicle I had bought used in many years - put a ton of money in it to try to figure out why it was heating up. I think it was a combination of steep climbs and high altitude. The final recomendation was to change out thermostats and water pump, but when I found out that GM did not recommend this I did not want to take a chance of voiding the 120,000 mile warrenty, (diesel motors are major bucks when they blow up) so off to trade-in land it went - went back to buying new vehicles.

Don't get me wrong, I loved the Suburban - it did everything great except for what I bought it for - and that was towing my 5000 lb trailer.

I also liked it for long road trips, but around town it was kind of a pain.


Ken J.

[HURST]

We came back from the International Rally last year(2002) with a outside temperature of 100+. Drove 60/65 with AC on and only went to 205 once just for a little while, then back down to 195/200. Not bad for what I carry around. And a stock 6.5. I can only hope my next truck will be as good.

[WKW]

Mr. Hurst,

Wish my 6.5 was that good. While in Arkansas my engine overheated and cracked a piston. I only had 70,000 on it.

WKW

[blackdog]

I had my 95 GMC fuel system go belly up in Gaithersberg MD on the way to Rehobeth Beach from Wisconsin. It cost me $1500 and a hotel stay to fix. I had the same initial symptoms before the trip and the dealer replaced the turbocharger, waste gate solenoid. It turns out that the real problem was the fuel distribution module, the fuel pump, and injector control(they all talk to each other)

I still get some bucking under a heavy pull after idling for any more than a few minutes. I have no idea why? It seems like the fuel in the lines gets heated and cause instability in injection. Once I have been moving for a mile or so after a long idling period the bucking goes away.

Also please take advantage of the service letter covering the incredibly frustrating wipers on the 94~99 trucks. After replacing wiper motors, relays, switches, to the tune of $500 I bypassed the circuit and had them just running at one speed with an on/off switch I installed on the dash. It turns out an under-rated land on the back of the relay board cracks and intermittently goes open, always in a downpour and always on an interstate! They now fix it for free and reimburse you for all the prior wasted money fixes.