1999 Tahoe - A Couple of Problems

[cqlink]

Just bought my first one (LT, 4X4, 87K on the clock, 5.7L) and it's great to drive but I believe I have some common problems. Can anyone shed some light?

1) 4WD indicator lights -- Sometimes they light. Sometimes they don't. Right now I'm in 2Hi. When the indicator light is not on, occasionally I can press the 2H button and it stays on for awhile then it goes off. Other times I press it and nothing lights. I'm afraid to try it in 4H for fear it might get stuck in 4H.

Before I purchased the truck, I pressed all the buttons to make sure 4X4 was working and even though the indicator lights were out at the time, I could hear the shift and 4X4 worked.

Switch? Shift motor? or ???

2) Headlights stay on when I start the truck. I know some models have daytime lights but mine seem to be just as bright in the day as they are at night. When I turn off the ignition, the lights go off. I don't own a Canadian model so I'm kind of confused.

I took the truck to an auto electric shop and he subscribed to a database listing possible causes but all he could find was the problem. The only solution was to purchase a switch (not sure if it's an OEM part) that when installed, allows the driver to override the "Daytime" mode.

The only sensor I see that should adjust for daytime and night mode seems to be in the back of the rearview mirror. I plan on shining a flashlight on it tonight to see if the light s adjust back into what should be the "daylight" mode.

3) Coolant. I learned about the intake leak a bit too late. Just topped coolant off with the orange Havoline coolant. will this stuff eat away at the intake gasket like the OEM stuff?

Thanks in advance for any insight!!!

 

[yukondale]

I have a 99 yukon that had the same problems.

First your lights are running light s and they won't go out during daylight hours.

Second, your switch is bad and you can replace that or maybe your main ground.

Third, flush the dexatron out and just use prestone antifreeze, prestone pump inhibitor and lubricant. you might already take in antifreeze, check your oil. and replace your hoses and clamps.

 

[TigerEyz3]

Can't answer your 4x4 question - only dealt with my rig, which is 2x4.

I've had my Tahoe since almost new (had 34k on it)... my DRL never seemed to change brightness regardless of environmental conditions. I just pulled the fuse, because I like to control when my lights are on/off and hated having to depress the e-brake to get them off when I was parked.

As far as the coolant situation, you'll want to replace the intake gaskets sooner rather than later. I've either had mine replaced or replaced them myself twice since I've had my truck (now has 260k miles on the original motor). I wouldn't worry about the coolant choice itself as long as you don't mix them (orange and green make for a very nasty situation in your motor).

 

[cqlink]

Thanks guys. I'll get rid of the coolant.

How much to swap the intake gasket at a local shop? I don't trust the dealer.

Also, forgot to add, I'm hear a "clicking" sound at my inside fuse box. Sounds like a dead battery "click" but not as loud.

 

[TigerEyz3]

$400+ for the job at most non-dealer locations... The gaskets themselves aren't expensive to purchase, it's the labor that gets ya.

Dead batteries don't "click"... sounds like you might have a bad relay though. Could be several different things in that area.

 

[cqlink]

Hey TigerEyz3,

I noticed on your mods list you have the updated Spider assy. Just what is that and should I replace mine when I swap the intake gaskets?

---------- Post added at 10:14 AM ---------- Previous post was at 09:33 AM ----------

Also, are there upper AND lower gaskets on my intake? Does a quote on replacing gaskets include both?

 

[TigerEyz3]

Hey TigerEyz3,

I noticed on your mods list you have the updated Spider assy. Just what is that and should I replace mine when I swap the intake gaskets?

---------- Post added at 10:14 AM ---------- Previous post was at 09:33 AM ----------

Also, are there upper AND lower gaskets on my intake? Does a quote on replacing gaskets include both?

Based on your phrasing, I'm not sure if you're familiar with what the spider ass'y is or not, but just in case you're not.... The new spider ass'y is basically the fuel regulator and fuel injectors (actual injectors on the ends on the new ass'y, which replace the poppets on the OEM spider. The poppets were known for clogging with the CA fuel additives).

I replaced the spider ass'y because I knew i was gonna be in there (2nd time around) and figured the legs and poppets on the OEM one were gonna be brittle and easily break. Not to mention the better fuel control of the new ass'y compared to the OEM one.

I can't say that you NEED to replace yours because I don't know the condition of your OEM ass'y. However, it made sense to me to do the job while I was in there (added the VMax spacer at the same time). The new ass'y costs a bit (~$317 (+s/h) when I got mine). Here's a LINK to where I got mine (everything included - despite the pic being for a V6, the part will have 8 legs/injectors).

There are upper and lower intakes on our trucks. The spider ass'y is located between the upper/lower intakes - directly under the upper intake runners (the black plastic that the throttle body is attached to). The lower intake is made of aluminum and mates to the block. On the pre-vortec motors (pre-96), the intake was a single metal unit.

The quote would depend on the shop. I've seen "book rates" for both. Obviously, doing both is gonna be better in the long run, but will cost a bit more (maybe an extra hour's labor).

 

[cqlink]

Thanks...I didn't see your answer before I had the intake gaskets done. I hope my fuel system continues to perform as it is since everything is buttoned back up. No problems with injectors so far here in Michigan.

 

[JB11]

you can pull the DRL fuse if you dont want the lights on during the day.

 

[TigerEyz3]

Thanks...I didn't see your answer before I had the intake gaskets done. I hope my fuel system continues to perform as it is since everything is buttoned back up. No problems with injectors so far here in Michigan.

You'll be fine... your truck is basically new (87k miles is just getting "broken-in" good) so you shouldn't have any issues whatsoever. Like I said, this was my second go-round with the intake gaskets.

Only fuel related issue I can think of that I encountered around that mileage mark was replacing my fuel pump - I think that was after 100k. Tranny was rebuilt around 150-160k.