A couple of days ago I picked up my 2003 Avalanche from my mechanic that was performing oil leak repairs, along with a few other items.
The main purpose of this repair was to address the large, supposedly oil, leaks that were getting worse over the past few months.
Below is one spot on my driveway where the truck was marking it's territory.
Probably not as bad as some, but I don't like the mess and it was getting worse.
I had already replaced the rocker arm cover gaskets and by the looks of things, the rear main seal was the main contributor.
This is a path I know all too well since I had this repair done to the 2004 EXT some time back.
And at 282K miles, it does not surprise me in the least.
The instructions I gave my mechanic was to replace the entire rear main seal and rear main seal plate as an assembly, instead of just trying to replace the seal by itself.
We learned that lesson on the EXT.
Next, I wanted the oil pan gasket replaced along with installing a new oil pickup tube o-ring.
The oil cooler block off plate adapter did not appear to be leaking, so we left that one alone.
I can easily take care of that gasket later, if I need to do so.
In addition, I wanted the intake manifold gaskets replaced since I was starting to get lean codes during very cold starts.
A typical failure point on these older engines and as it turned out, was a very good choice.
He was told to go over the engine as best he could to make sure all of the fluid leaks were addressed.
Replacing the rear main seal assembly and the oil pan gasket took care of the leaks from those locations, but there was more.
When replacing the intake manifold gaskets and getting a good look in that area, he found the engine lifter valley cover gasket was wasted and was allowing oil to run down the rear of the engine and over the bell housing.
That is seldom mentioned in most conversations about engine oil leaks, so it had not crossed my mind.
Regardless, the assorted gaskets in that area were also replaced and all of the oil all over the engine was cleaned up.
Once he was happy with the engine oil leak repairs and clean up, he called to update what he had done and what else he had observed.
His question to me was did I know when and who had done a transmission pan service on this truck in the past.
I told him I suspected which shop may have done that work, but I did not know for sure when the previous owner had that work done.
I had not had that work done since I have owned the truck.
I was told the transmission pan had been sealed with silicone and it not only was it a poor job, but was old, messy and leaking transmission fluid, which was contributing to the mess on the ground.
He already knew what I was wanting to have done, but just wanted to check to be sure.
So, we finished this job up with a pan drop fluid change, transmission cooler line clean out, new filter and fresh fluid top off.
It was reported that both the engine oil pan and the transmission pan were remarkably clean and there were no signs of excessive wear or anything else to be overly concerned about.
Everything, like the cam lobes and such, that they could see with the valley cover off, looked great.
The oil pickup tube o-ring was getting hard and showing signs of flattening on the edges, even though I did not have any complaints with the engine oil pressure.
I figured as long as the oil pan was off, now would be a good time to install the new o-ring.
The only other item was the replacement of the OEM plastic oil galley barbell with a new billet barbell.
I drove the truck the night I got it back and across town and back yesterday.
All fluid levels, temperatures and pressures are good and stable and the engine and transmission are working as expected.
As a lot of people have been experiencing lately, we have had massive amounts of rain here, so until the driveway has had a chance to dry up, I will not know for sure if all of the leaks have been successfully addressed.
I'm pretty sure that they have been and that makes me happy.
