Ask the experts --> you guys

[ib516]

OK, here is my situation. I own a 2001 Chev Venture minivan that I bought used about a year ago. It now has 97,000 Km (60,000 miles) on it, and I just changed the oil.

The oil had 4700 Km (~3000 miles) on it. It was last changed at the local Wal*Mart. I like to do it myself, but I have to get it done once a year (in winter) at a shop because it is cold here, and my garage isn't heated. They used the Wal*Mart 5w30 Tech 2000 oil, and a Pennzoil filter.

The OLM said the oil had 45% life left with the 4700 Km on it. We live about 10 Km (6 miles) out of town, and the van is used by my wife as a commuter/run about. I'd say it has 75% city, 25% hwy on the oil (roughly).

Here's the problem. When I changed the oil, it didn't appear totally black or super dirty, but there was sludge on the top of the oil filter (on the metal part within the rubber gasket area). I always keep up on my maintenence, and I have never seen this before. That oil did run in the van when it was very cold out (-30*C) for a few weeks.

I think it was a combination of cheap oil (my fault) lots of city driving, and cold weather that caused the sludge.

My wife is planning to go to her mothers in a few days (hence the oil change) which is about 1600 Km round trip (1000 miles). My plan is that all the highway driving she is going to do should "clean up" the inside of the engine with the fresh oil, then I will dump it when she gets home (it will have around 1000 miles on the oil), and put the Synthetic Valvoline 10w30 in I have in the garage. I put store brand 10w30 in it for the trip, because I had it sitting around. I didn't have enough, so I needed an extra liter of oil to make it hit the full mark. So what's in it is 4L of 10w30 store brand, and 1L of Quaker state full synthetic 10w30. I have a FRAM filter on it.

What do you think of the plan? Will that get rid of any possible sludge inside the engine? I'm hoping the new oil will have enough detergency to hold the sludge in suspension for the trip until I get to dump it out and put quality oil in it.

 

[G-MAN]

The first thing you need to do is an oil analysis to see if your 3.4 has developed in infamous intake manifold leak which allows coolant to escape into the engine. My 3.4 developed the leak and it completely sludged up the engine by the time I realized what was going on. 99.9% of all 3.1 and 3.4 GM V6s will eventually have this problem, so the chances are good you've got it.

If you catch it early and get the manifold gasket replaced you can avoid some serious damage to the main and rod bearings.

 

[ib516]

I have had to add a small amount of coolant each time I change the oil, probably about 1/2 a quart.

The oil doesn't look milky though, and I have already dumped the used oil out of the drain pan into a 5 gal bucket with other used oil already in it from different vehicles.

 

[m2200b]

So K will be about 50.
Pb 10-15 if you are lucky.
Test it for $20 while its still
just leaking a little.

 

[m2200b]

Test the oil when you change in 1000-2000. Short OCI do help with keeping coolant leaks under control from a damage to the bearing standpoint.Add some GM coolant tabs now. Cross your fingers.

The oil won't be milkey with that level leak.
Also do a visual exam for leaks in the daylight around the intakes. Its easier to see the leak on a 3.8 GM than yours.

 

[ib516]

I called a friend of mine that is a GM tech. He asked me a few questions and confirmed it is the intake gasket. SON OF A !!!!

Looks like I have some wrenching and parts cleaning to do this week.

Thanks G-Man for jogging my memory so I put 2 and 2 together to = intake gasket.

 

[Al]

Yea its 100% chance that a 3.1/3.4 GM will fail in 50K miles. It would be a rare one that didn't. Yaaaaa for GM

 

[m2200b]

100% does not mean its leaking now. Still test it
to determine if you have a leak now.

 

[GoldenRod]

I'm happy to hear that you do your own wrenching. I have no sympathy for people who don't.

 

[G-MAN]

quote:

---

Originally posted by GoldenRod:
I'm happy to hear that you do your own wrenching. I have no sympathy for people who don't.

---

There's a big difference between those who don't and those who can't. There's nothing worse than getting in the middle of something and realizing you're in over your head.

I consider myself pretty proficient with a wrench and I do most routine maintenance on my cars. But when it came to the intake gasket on my mini van I let my trusted mechanic do the work.

 

[Winston]

I have heard the FelPro problems solver gaskets are good. I would not trust the newly re-re-re-re-designed GM gasket, but that is just me.

There was a link on BITOG about the problem solver gasket. Felpro talked about the developement of it. It was interesting.

 

[ib516]

We got it apart, and sure enough, it WAS leaking - but not too bad. Just goes to show that doing your own oil changes is the best policy. I doubt anyone would have looked for the sludge I found, or cared if they would have seen it at a shop. The flunkies at Wal*Mart missed it.

On the advice of my GM tech buddy, I bought and used the latest Fel-Pro gaskets. Just looking at them, you can tell they are 300% better than what GM put in there. The original ones were some type of fiberous material, with a very thin layer of silicone around the water passages. The Fel-Pro gaskets are made of aluminium, and have very thick rubbery looking sealant around all of the water passages.

I took the whole dang engine apart, only thing left on it was the heads. Took all the parts down to the car wash and sprayed the sludge off of them. Used brake cleaner to spray out the inside of the pushrods in case there was any sludge in there. Changed oil, sent wife on 500 mile trip to her mothers, then my BIL changed the oil there, 5w30 Valvoline synpower, and added a 1/2 quart (500mL) bottle of detergent additive I picked up at a local auto parts store and sent with the wife when she left. She drove it home a couple of days later. Has been running fine since (about a month now). Oil has 1800 Km (about 1200 miles) on it now, and looks good. That dexcool in the oil sure sludged up the insides of the engine - and mine was a minor leak.

While I was at it, I changed all the idler pulleys (some had slightly noisy bearings), the tensioner, spark plugs, wires, thermostat, and a few other odds and ends. Belt had been replaced recently, so it was OK. Should be good for another 60,000 miles now.

Anyway - all's well that ends well. Thanks for the help.

 

[ib516]

Just as an update, it's been almost 2 years since, and the thing is still running fine. It does have a slight "tick" when cold - don't know if it is a lifter or piston slap, but it doesn't use any oil.

Looks like I caught it in time. Van has about ~80,000 miles (~132,000 Km) on it now.

 

[02zx9r]

good job

 

[Drivebelt]

Good save guys.

The internet is a great tool (source of information) for just about any hobby.

Quote:
There's a big difference between those who don't and those who can't. There's nothing worse than getting in the middle of something and realizing you're in over your head.


Ya, I just hate it when I put something back together and there are leftover parts … … …hmmmm …. I wonder if those are important.

 

[oilboy123]

Have you run Auto-RX? I would run it and it will probably get rid of the tick if it is a lifter tick. Piston I don't think soo.
Also it should clean any antifreeze left behind.