View Full Version : what to do? rear main seal leak on daily driver
laxking012
08-08-2011, 08:33 AM
So my 1994 GMC 1500 v6 has a rear main seal leak as well as the valve covers a little. Its got 195000 miles on it. I don't know if I should go ahead and just get these leaks taken care of? Or maybe have the whole engine gone over and rebuilt? Perhaps just find a new engine? Or even I guess just find another vehicle? What does anyone think?
andamo
08-08-2011, 09:04 AM
It all depends on what you want to do. If the body and driveline are in good condition and the cash for another vehicle is tight, a rebuilt motor might be the way to go. At the miles you're talking about, all the mechanical components are close to being needed to be replaced/rebuilt. Just sit down and get prices on the different scenario's you've said and do your homework.
DirkaDirka
08-08-2011, 09:04 AM
With that many miles on it it might be best to either replace or have the engine rebuilt.
Harbone
08-08-2011, 10:28 AM
How bad is the rear main leaking? seepage, constant drip or gushing out?
laxking012
08-08-2011, 11:47 AM
seems like it's just a seep that really only happens when the oil is hot.. I never notice that it's leaked on the short just up the street kind of trips. I see it when the trips start getting over like 15 minutes.
Harbone
08-08-2011, 01:01 PM
That motor is notorious for a rear seal seep. I have a delivery van thats got 330K miles on it and that seal has been seeping since 100K. its never got past that and has never been low on oil between changes. If its just a seep, keep an eye on it and keep driving.
laxking012
08-08-2011, 01:07 PM
Well this morning I changed the oil, that's when I noticed the leak, it was down to the add level. But its only been 2000 miles since the last oil change. So I took it to the place I used to get service before I started doing it myself. They put it up on the lift to get a better view and looked at it for me for free, and confirmed the rear main seal and valve cover leaks.
grimratter
08-08-2011, 05:17 PM
With a lot of miles on the engine it may be a bad seal, but something a lot of people don't realize is that you need to pull a vacuum on the crank case or it will find a way to release the pressure, and the rear main is usually the weakest point of release. Check your PCV valve, or better yet, install a new one and make sure you have it on a good strong vacuum source. I've corrected dripping rear mains with this method.
MEMRACING62
08-08-2011, 07:08 PM
I wouldn't worry about oil consumption less than one quart per thousand miles, with almost 200k....drive & enjoy.....one quart in 2k is nothing for an engine that age & milage. jmo
TheYellaBrick
08-08-2011, 07:32 PM
I've a 94 Astro with that 4.3 at 220k and it's seeping at that rear main and valve covers. I've cinched down the VC's and am living w/the main seal. My main prob is a burnt valve on #5 ex. The rest of the cyls are 125lbs straight across and it doesn't burn a drop. I'd still be driving it except for that dead hole. Even on 5 cyls I can still tow a loaded trailer without too much grunting!
----------
I wouldn't worry about oil consumption less than one quart per thousand miles, with almost 200k....drive & enjoy.....one quart in 2k is nothing for an engine that age & milage. jmo
X2
And a hellova lot cheaper than PAYMENTS :lol:
Scooterz
08-09-2011, 09:16 AM
JMO: put some valve cover gaskets on (do not over tighten them). Unless you are seeing a big puddle under the truck everytime, drive it. Keep an eye on oil level. rear main seals are notorious for going out anyways... it's a 20.00 seal with a TON of R&R labor... drive it.
txhunter69
09-05-2011, 08:07 PM
i have the same truck and at 258k i bought a new/used motor for 225 best investment yet still drivin strong
paid 750 for the truck and have been drivin it for 2 years
oldandtired
09-08-2011, 08:43 AM
JMO: put some valve cover gaskets on (do not over tighten them). Unless you are seeing a big puddle under the truck everytime, drive it. Keep an eye on oil level. rear main seals are notorious for going out anyways... it's a 20.00 seal with a TON of R&R labor... drive it.
Agree - just drive it. What if you spend all the time to change the seal and it has a groove worn in the crank??