Coolant leak in a 99 votec Yukon???

[yukonjon]

I've got a coolant leak from the right side of my engine, I think right above the starter. Drips down the starter but can't see anything on or near the header. Is there a freeze plug near that area or could it be something else there. I plan on tearing into but kinda want to know what to expect before I do it. Anyone had this issue or could give me some insight on what it is? Thanks

 

[tlamot01]

I'm willing to bet money that if you look further up the rear of the engine, you will see coolant leaking from the valley of the plastic lower intake manifold. It's not very obvious since the engine leans backward. Any leak will drain down your engine and appear to be coming from right above the starter. This is the most common coolant leak for Vortec engines.
Luckily, it is an easy fix since the gasket sets have been re-designed.
Also, while you've got it all pulled apart, you might as well replace all the upper gaskets since a complete upper rebuild kit is only about 50 bucks more. And pulling the heads off once the upper manifold is removed is pretty easy. Took me about eight hours to complete this job.

Recommended parts:

Just the Intake Set: http://www.amazon.com/Dorman-615-30...tomotive&Make=GMC|48&Year=1998|1998&carId=001

The Full Upper Set: http://www.amazon.com/Fel-Pro-HS773...tomotive&Make=GMC|48&Year=1998|1998&carId=001
Will also require new Head Bolts: http://www.amazon.com/Fel-Pro-ES72856-Misc-Set/dp/B000C2AHWC/ref=pd_bxgy_auto_text_b

Optional (while you've got everything torn apart) parts:

MPFI upgraded fuel injector pac: http://www.amazon.com/Delphi-FJ10566-Fuel-Injector/dp/B000TYLIFS/ <<--- Highly recommend this upgrade!!

AC Delco Spark Plugs: http://www.amazon.com/ACDelco-41-993-Professional-Iridium-Spark/dp/B000NWA6TU/

AC Delco Wire Set: http://www.amazon.com/ACDelco-9718Q-Spark-Plug-Wire/dp/B000S2SRXC/

Also a good opportunity to get your valve covers powder coated at your local shop.
Amazon is the best price for the MPFI upgrade, but everything else might be had cheaper at your local parts store (I recommend AdvanceAutoParts.com with a coupon code)

 

[yukonjon]

After checking everything out I believe your right. I was planning on doing the spider upgrade. Guess the time is now. Thanks a ton for all the part info. This forum is such a great help.

 

[tlamot01]

Hey, always glad to help. I hated seeing these trucks getting murdered during the great government 'Cash for Clunkers' debacle.
I wonder how may of the obe trucks got the axe that had nothing wrong with them other than a coolant leak.

---------- Post added at 03:15 PM ---------- Previous post was at 03:10 PM ----------

I have some pictures of this install that might help you. Will upload them this afternoon.

 

[yukonjon]

Id appreciate the pics if you get them loaded. I've got a little tick in the valves too I'll have to take care of at the same time.

 

[992dr]

The lower is very common to go. It seems no matter where it leaks, it always goes out the back. Mine leaked at the front and only dripped out back. When my heater hose fitting went, it also leaked out back. The best thing to do is a leakdown test but, if you cant do it, what I did was got under it after letting it sit to cool and dry with a pretty bright flashlite. It is very noticeable to see where the coolant is coming from then because it dries white.

This is a popular set for our trucks. No need to get the heads kit, unless you are going to do them as well.
http://www.amazon.com/Fel-Pro-MS90131-Manifold-Gasket-Set/dp/B000C2GE4C/ref=pd_sim_auto_6

 

[Gregski]

Saying I've got a coolant leak is like saying I gotta Chebby Tahoe/Yukon, LOL, say no more, hope you get it fingered out

 

[billytheadult]

You should be able to do this on your own, it's not a big deal, if you ever changed gaskets before you'll do it. Good luck!

 

[tlamot01]

Jon, did you find the time to make this repair yet?

 

[sparg93]

also check the quick disconnect heater hose!! It's the hose that comes out right next to the manifold and in 99% of cases, it's completely corroded and needs to be changed...its only a matter of time before i splits.

Check out this photo I took. The quick disconnect is that metal connector with the plastic tab on the bottom right hand portion of the manifold.



As folks have said up above, it could also be a manifold gasket leaking as this happens regularly on our motors. If you're going to take apart the engine, do EVERYTHING at once. This is the time to perform a complete tuneup, change lots of gaskets, upgrade fuel injection AND replaced that heater hose connect. If you try to replace the heater hose connect with the manifold on the engine, shavings will fall into the engine.

If you go this route (overhaul), read up extensively on how to replace the manifold gasket (tips & techniques), know EVERY bolt's torque setting and give yourself about three days before attempting...and def make sure you have another vehicle.

Manifold gasket is a big job and if you haven't done it before, there is a chance you will run out of time before work starts back up on Monday. Also, take LOTS of photos...seriously, take over 30 photos of every angle possible if you haven't done this before.

However, if you do all this in one shot, you just completed a pretty serious job your Tahoe will thank you for.