Richard69

Hi, a mechanic changed the valve cover gasket on my 1995 Ls400 about 3 months ago. I noticed a small oil leak about a week ago. Now I can smell the burnt oil. It seems to be leaking near the corner of the driver's side, right behind the timing belt cover. There's a lot of oil sludge there that wasn't there before. Is it possible that they didn't do something right? It's actually leaking more than before they replaced it. I question this mechanics work because one of the items they charged me for was a throttle body gasket. When I removed the throttle body, the gasket, it was old and brittle, and the back side of the throttle body was extremely dirty. I also don't think they changed the rubber seals for the "new" sparkplugs because they looked dirty. I also had to change the spark plug wires because one of the covers that seal the top of the hole was missing a quarter of rubber.

The other thing I was wondering, when the valve cover gaskets are replaced, is the inside of the valve cover usually cleaned, or is it left as is? When I removed the oil cap, I could see how dirty it was (almost like burnt oil stuck to the walls).

400fanboy

Tube seals are the #1 "while you're in there" thing to do if you pull the covers.

I mean if you're questioning the work of the mechanic, and you've found items which you were charged for but not completed... then yes the entire job is in question.

Richard69

Couldn't get camera close and focus, but leak is behind cover


These don't look new to me

Inside oil cap

deanshark

It is VERY possible that when they put the valve cover back on with the new gasket that the gasket moved a bit and it's not sealed so now it's leaking more then before. I'd bring it back. If it's from there then it's their fault. Or, it could be leaking from the cam seal. (not their fault) And no, those tube seals are not new. I'd get this straightened out with them and find a different mechanic.

I do notice that the electrical connector for the #1 fuel injector doesn't have the clip on it to hold it in tight. That could be a problem in the future. If the engine vibrates it could come loose and you wont have fuel going to that cylinder.

Richard69

Thanks, the picture with the #1 fuel injector clip is a few weeks old. I replaced it when I changed the spark plug wires, coolant temp sensor and sender. Also replaced a couple of other clips that were disintegrating. The zip tie on the timing belt cover is temporary as they were all missing when I got the car back from having the valve cover gasket replaced.

400fanboy

Wait, the cover was missing bolts when you got it back? It's just red flag after red flag.

What else is missing bolts....

& I'm going to guess they probably re-used the 1-time-use bolts\seals on the valve covers too.

Leak is also possible if they used non-OEM gasket. It's like 3 bucks or whatever it is, why you wouldn't use OEM is beyond me.

Richard69

It was just the bolts that secure the plastic timing belt covers on both sides. I noticed those when I heard what sounds like a noisy pully coming from under both sides under those covers. That noise started after I picked up the car from the valve cover gasket replacement. I didn't think it was associated with what they did, and quite possibly could be coming from other pulleys or the cooling fan. It did get quieter after I properly closed the timing belt covers and secured it with zip ties. In the Lexus report, the timing belt was supposedly changed before I bought the vehicle, but no sticker was put anywhere.

Richard69

Oh, and after just watching a couple of YouTube vids, it looks like the leak is right where the drivers side front half moon is, to better describe the location.

aptoslexus

I'd get another mechanic. Those valve covers should have been cleaned. It doesn't look like the tube seals were replaced. And I doubt the half-moons were done, so it could be leaking there. This is a classic example of why it's better to do your own work, if you are able. You care about your car, but to a mechanic, it's just "how quick can I get this done to maximize profit?". You should have an itemized list of what they put in there. If they did the tube seals, it will be in the list. But in any case, that isn't a great job by the shop.

Richard69

Thanks to all you guys and the help of this Forum, I'm learning quick. I've already bought most of the front suspension and now feel confident enough that I've started work on that. I'm tempted to not even have this mechanic fix their mistake given everything I found out because who's to say it won't be worse? I think I can do it myself now. You're right about working on these cars yourself. I've been to 3 mechanics since I bought the car. Not saying they're all bad, but I haven't had good luck. I really love my LS400. There's something about it and these cars deserve to be well maintained. I've enjoyed learning how to fix it, and it's even spread to me starting to tackle things on my Jeep Grand Cherokee (like the engine oil cooler), that I would never of thought I could do before.

Anyway, thanks to all of you for your help. I'm putting the knowledge to good use.