whitelotus

Help! My '99 GS300 all of a sudden won't run. My husband started it yesterday and it made a knocking sound, so he turned it off immediately. We thought the timing belt was broken, even though it's 3 miles short of 80k. Now the starter sounds like it's "sliding," like it has low compression. He compression tested it last night and can't get higher than 75psi on all 6 cylinders.

We're pretty sure that the timing belt is fine and there are no broken plugs. Any ideas what it could be? The only odd coincidence is that we've been using traction control in the snow a lot, and the other day, he was spinning the wheels in the ice outside our driveway and the engine almost died. Also, it was running rougher than usual in the cold a few days ago, but other than that there have been no warning signs.

Any ideas? We'd just take it in to a shop, but I'm waiting on some recommendations for a good independent in Denver, so figured I'd try to rule out some possibilities in the meantime.

Any thoughts would be MUCH appreciated. Thanks.

Shawnmack

Any kind of CEL vsc lights appear?

whitelotus

That's a good question. He was concentrating on the engine knock, not looking at the panel. Now, since the engine won't start, all the lights are on. Unless the VSC light shouldn't be on at the accessory position.

It occurred to me this morning that the VSC might be malfunctioning, but that didn't seem to explain the engine knock when it started the first time.

whitelotus

Okay, so I found a Toyota/Lexus specialist and my husband spoke with the owner a little while ago. He seems to think the problem is with the VVTi, and that the low compression might because of the oil/gas mixture in the cylinder from performing the compression test.

What I left out before was that the oil was low (not dry, but low) and the temperature in the garage has been only about 25 degrees. I know insufficient lubrication at the top of the camshaft can cause horrid engine knocks (my '01 Mercedes C320 had a bad oil pump design and the thing clacked like a typewriter), but could it also screw up the VVTi?

Going to have it towed over there tomorrow and see what's actually going on. Just trying to figure out if I need to mortgage the house for the repairs!

Dx3

iTrader: (13)

[QUOTE=whitelotus;2274599]. I know insufficient lubrication at the top of the camshaft can cause horrid engine knocks (my '01 Mercedes C320 had a bad oil pump design and the thing clacked like a typewriter), but could it also screw up the VVTi?

[QUOTE]

Wow - I am impressed at your knowlege. Most women I run into couldn't tell you where the dipstick is

Good Luck and let us know. I know very little about the VVT-I on these cars so I am eager to hear what he finds out.

Jonny

VVT-i

I second DX3 about your knowledges.

The VVT-i controller uses oil pressure to advance or retard valve timing. It's possible that the temp. is too cold for the oil to feed the VVT-i controller and caused the engine to knock or stalled when you first started up. When your husband shut the engine off may cause the gasoline to flooded the engine that why you got low compression on all 6 cylinder.
I have seen this problem all the time especially when it's real cold and people won't let the car idle up or let the computer adjust air/fuel mixture to correct itself. You can just remove the spark plugs, clean it up with carb. cleaner and use shop air blow inside the combustion chambers.
Good luck.

whitelotus

Awww shucks, guys. I'm not about to run out and rebuild an engine or anything, but at least my eyes don't glaze over when the conversation turns technical.

VVT-i: Thanks, that's the first thorough explanation I've heard about how the VVT-i actually works. Looks like you're exactly right. We got it running, and now that the oil has burned off, the check engine light is out and it's running perfectly. Do you think there's any sense in having it looked at, or should that be it?

Never had these kind of problems in California. Guess it's going to have to get used to being a Colorado car now. LOL.

VVT-i

I'm glad you got she running. I think you should be fine without going to the shop.

clubfoot

Don't forget to top off the oil level!

whitelotus

Definitely! Already did. Actually, she's due for an oil change 12 miles ago.