86 GMC Sierra Classic 2500 questions

[dfrank]

Originally Posted by gmcnoob

Good morning. Can anyone tell me what this little black box is/was for on the left side of four-wheel-drive?

Maybe a trailer brake controller?

[gmcnoob]

I want to share the experience I had with my local auto repair shop today. My long-awaited BFGoodrich 33" x 16.5" x 12.5" tires were finally manufactured and delivered to me at the beginning of January. Since I do not have the tools or the experience to mount and balance tires I brought them to the local shop to have them installed along with a state inspection. My first complaint is the fact that I called them five days later to find out what was taking so long and they told me that it had been completed the previous day. I find it strange that it took that long for such a simple job and that nobody gave me a call to let me know it had been completed. But that's not all. When I brought the truck in I made them aware that the tail lights do not come on when I turn the headlights on. They knowingly passed the inspection without fixing the tail light issue. Does anybody find this unusual? I didn't bring it in just to get a sticker on my windshield. I wanted the problem to be fixed. I let that slide because at least I passed inspection and I wasn't charged to have the lights fixed. I'll get that done by another shop. But here is the part you guys are really going to enjoy. They installed the closed ended center caps over the locking hubs. Yes, you read that right. What do you think of that? Now I don't mean to nitpick but they also failed to put my valve stem caps back on.

Obviously they won't be getting my business again. They turned what should have been a simple job for them into a complete disaster. I wonder if they have any idea what they're doing at all. I just can't get over them putting closed ended caps over the locking hubs. Unbelievable! What would you do in this situation?

[dfrank]

Originally Posted by gmcnoob

I want to share the experience I had with my local auto repair shop today. My long-awaited BFGoodrich 33" x 16.5" x 12.5" tires were finally manufactured and delivered to me at the beginning of January. Since I do not have the tools or the experience to mount and balance tires I brought them to the local shop to have them installed along with a state inspection. My first complaint is the fact that I called them five days later to find out what was taking so long and they told me that it had been completed the previous day. I find it strange that it took that long for such a simple job and that nobody gave me a call to let me know it had been completed. But that's not all. When I brought the truck in I made them aware that the tail lights do not come on when I turn the headlights on. They knowingly passed the inspection without fixing the tail light issue. Does anybody find this unusual? I didn't bring it in just to get a sticker on my windshield. I wanted the problem to be fixed. I let that slide because at least I passed inspection and I wasn't charged to have the lights fixed. I'll get that done by another shop. But here is the part you guys are really going to enjoy. They installed the closed ended center caps over the locking hubs. Yes, you read that right. What do you think of that? Now I don't mean to nitpick but they also failed to put my valve stem caps back on.

Obviously they won't be getting my business again. They turned what should have been a simple job for them into a complete disaster. I wonder if they have any idea what they're doing at all. I just can't get over them putting closed ended caps over the locking hubs. Unbelievable! What would you do in this situation?

What I would do? I would fix it myself since I have the tools and no how. If I where you and didn't have the experience or tools than I would find another shop

[gmcnoob]

I will. I'm just blown away by this experience. What kind of mechanic covers a manual locking hub with a closed cap? He should find a new occupation.

[motornut]

Originally Posted by gmcnoob

I will. I'm just blown away by this experience. What kind of mechanic covers a manual locking hub with a closed cap? He should find a new occupation.

sounds like they lost a few parts and found some others, maybe that's "his" new occupation.

[gmcnoob]

Originally Posted by motornut

sounds like they lost a few parts and found some others, maybe that's "his" new occupation.

I hope the wheels don't come loose when I'm going down the road.

Anyway, moving on.... The attached picture is the water temperature sensor if I'm not mistaken. It looks like the wire is just wrapped around the sensor. It doesn't look right to me. Sometimes the temperature gauge will show normal temperature and sometimes just get stuck at cold. Could this be the culprit? It seems that there should be a plastic connector or something. Would replacing this be a good place to start?

[motornut]

Yes, it looks like it needs a new end,lots of parts places carry that .

[gmcnoob]

I tightened up the wire and at least now I'm getting a reading but it seems low. After a 15 minute drive it still stays right around what you see in the picture. Is it low or normal?

[gmcnoob]

Also after reading probably 100 threads on this matter I still can't get my tail lights and rear side markers to work. I was told that these lights are on the same connection as the dome and courtesy lights and they work. This is what I have noticed. The headlight switch dimmer connector is slightly melted. When I check all of the wires on the connector I am getting power on some of the wires but definitely not the brown one. Where should I go from here? There is definitely no power to the brown wire at the rear when the connector it is connected to the headlight switch and the lights turned and lights on. Everything looks good from the rear all the way to that melted connector. I assume I need to replace that connector. Any advice on this one? Thanks in advance especially motornut for taking the time to help me out.

Thanks to the advice I received on here the only thing I've had to bring the truck to the mechanic for was installing the tires. I have been able to fix every other problem myself so far. And the truck is running great!

[gmcnoob]

Originally Posted by motornut

do yourself a favour and get rid of those blue connecters
they cause lots of probs, basicly cutting wires,allows moisture/salt in
they prob used it to connect a trailer harness.
may have removed the plugs too.
the cluster dimmer is controlled by a coil of wire that can burn out in spots,
a rheostat,if the switch is out (of dash)you can usally see it,might see the burn marks too
thats why it can work off and on when twisting the nob
the od goes to 99,999 then 0,later years have another digit

I want to apologize for not taking your advise when you said to get rid of the blue connectors. It turns out the connection for the tail lights, side markers and license plate lamps was bad.... I wish I had listened. I finally did what you said and now all of the lights work.

I promise I will listen this time. So I replaced the coolant temperature sensor along with the thermostat after finding out that it was stuck open. Now after about five minutes the gauge approaches 260°. I'm not feeling a whole lot of pressure in the upper radiator hose and I'm getting a squealing noise on occasion. I'm thinking this might be the water pump. Is there something else I should look at first?

I don't know if it matters but I replaced the thermostat with one of those failsafe ones. After-the-fact I realized that might have been a bad idea. The one that was in there was a Robertshaw 330-180. I'm thinking I probably should have replaced it with that same one. Everything seemed fine when the thermostat was stuck open and it was running cold.

Now my question is does it sound like the water pump needs to be replaced or something else? Any advice on this issue?

[gmcnoob]

Well, I decided to put the old coolant temperature sensor back on and now the gauge is reading perfectly. There was nothing wrong with it to begin with. The gauge was reading so high with the new sensor that I was shutting it off before the new thermostat even had a chance to open. I thought I had a bad water pump but apparently it's working. I still get the squealing noise until it warms up a bit. Not sure what that's all about.

[gmcnoob]

Here's an update for anybody who cares or wants to comment. I have been working hard on this thing and almost everything is finally working the way it should. The only problem I still have is the oil pooling up on the intake due to broken valve cover bolts. I have done everything to try to get them out with no luck. I'm finally caving in and I'm going to bring it to my local shop to see what they can do.

The old mufflers were all rusty and had holes in them so I decided to replace them. I went with glass packs due to the fact that they're inexpensive. It actually sounds really good and I think it may have even improved the performance.

The BFGoodrich all-terrain tires are working out perfectly. We have gotten a lot of snow on the east coast recently and this thing drives right through it as if it's not even there. I'm having a lot of fun.

[54earl]

The squealing noise is most likely a loose, or worn out fan belt.

[54earl]

double post

[gmcnoob]

Originally Posted by 54earl

The squealing noise is most likely a loose, or worn out fan belt.

Thanks. That's the next thing I will replace.

[motornut]

sometimes a broom stick from the engine parts,held against your ear,
will let you narrow it down,like a worn bearing
avoid the moving parts! lol

[Liberty]

I don't know if you fixed your engine trouble yet.
But my 82 C10 had the same power problem.

Ended up being a plugged up pancake style catalytic converter.

Now my truck was old enough to legally remove the cat in Texas, but since yours is an 86 it will have to be replaced.

I'm assuming since your mufflers were toast that the original cat is still in place.

Also your squeaking could be the power steering pump giving up, mine kind of knocks now, but i wouldn't be surprised if it started squeaking too.

[gmcnoob]

So I dropped it off at the local mechanic today to have them fix those broken valve cover bolts. The guy said he couldn't even give me an estimate until he took a look at it. I was wondering if anyone could give me an idea of what this might cost me. Two of the valve cover bolts are broken on the passenger side closest to the intake and of course it's losing lots of oil. There is no bolt exposed to grab onto. I didn't want to dive into this myself and possibly make it worse.

If anyone has any idea what this might cost best case/worst case scenario I'd appreciate the information. It should be pretty simple for an experienced mechanic right?

[Liberty]

He'll just pull them out with some bolt pullers, not that hard really. He'll probably go ahead and replace the gaskets too. Id say it might run you a little over $100.

[gmcnoob]

Originally Posted by Liberty

He'll just pull them out with some bolt pullers, not that hard really. He'll probably go ahead and replace the gaskets too. Id say it might run you a little over $100.

That's a relief! Well worth it to get rid of this leak. I can deal with that. Thank you very much for the information.

[gmcnoob]

Well, now I am totally bummed out. Got my truck back and they definitely fixed the valve cover bolts issue and sealed it up nicely yet there is still oil pooling up. I trust that they did what I asked them to do which was to remove the broken bolts and put new valve cover gaskets in place. But yet I still have oil leaking onto the ground. Not nearly as much as before but it is not fixed. Is it possible that oil is pushing through those intake manifold bolts? Is there any other reason oil would be pooling up there? Did they not get the job done properly? I'm almost ashamed to say that I paid $350 and still have the same problem I had when I brought it in. Any advice, guidance or suggestions would be greatly appreciated.

[gmcnoob]

A closer pic of the oil pool.

[gmcnoob]

And mechanic notes...

[Liberty]

My suggestion would be to wipe the oil off and run the engine with the hood up.
Try and see if you can see where the oil is coming from. If the valve covers were leaking there would very likely be smoke coming off the exhaust manifolds.
I'm suspecting that breather up top, but I'm not seeing oil on top of the valve cover so thats probably not it.

[Liberty]

Oh also, replace that heater hose. It looks about done, mine blew off recently and it was that exact identical hose and it didnt look half that swollen. If that sucker blows off you'll overheat the engine and have to redo the gaskets again.