l24 exhaust leak?

[nismosilvia]

So I've been putting in the time trying to get a jtin dats for cruzing duty. I recently redid every hose and gasket involving the intake and exhaust and I'm still getting white smoke in the engine bay when I seafoam. Are felpro gaskets just Shit or am I underestemaiting just how hard I have to tighten the manifold bolts? I'm stumped can't figure it out and rly want to smog this car so I can start driving. I've let the motor get hot put on the welding gloves retorqed bolts same symptoms. Seems to be smoking out of the back of the manifold l24 motor. Changed the cracked stock manifold too still smoking Arg. Any suggestions greatly appreciated.

[I'm BLUE]

Fel-Pro gasket's are generally good ones to use.

 

I'm "assuming" bolts are over-torqued at this point.

Means that you tried to re-torque them all to get it to seal.

 

Did you check your exhaust manifold sealing surface for warpage before installing it ?

 

.... Did you torque the manifold bolts to proper specs per your repair manual ?

[TFM1066]

The six cylinder manifolds generally warp in a bow fashion, (#1 and #6 higher than the rest of the ports) surfacing the manifold itself won’t fix the problem making the exhaust impossible to seal. This has been a common complaint with most 6 cyl L-series motors. About the only fix is to install a header, new manifold I would think by now are no longer available.

[banzai510(hainz)]

Dont Seafoam

[72240z]

A machine shop can resurface the mani and true it up just fine. People do it all the time.

 

Seafoam is bogus imho

[datzenmike]

L24, 240sx? Is this a 240z car from the '70s????

 

Well the obvious thing is to stop using seafoam. Does it smoke otherwise? If not problem fixed.

[nismosilvia]

You guys are awesome, I really appreciate all your great information. I did put the straightest metal ruler I had on the head and manifold and they all seemed straight to my eyes. I pulled of the valve cover checked for tolerances and everything was good, everything looked clean too. The motor definitely runs a lot smoother now than it did before. I put on some universal msa wires and new plugs and that was a big improvement. All in all now it sounds less like a 4cylinder 1950s Ford tractor ha. I think I'm just over paranoid about smog because I've never done it before and its led me to do extreme stuff like seafoam and cat cleaners. Anyways thanks again

[72240z]

See thats the big prob with the manis that lead to a lot of misconceptions. Its extremely hard to check the surface with a ruler. Mainly because without the proper tools you cant see the differences between the outer sides and center. a machine shop has the means to resurface and check it properly.

 

Mike seafoam is supposed to smoke but not from under the hood lol

[Z-train]

Seafoam is about the only thing in a can that works.

 

Pull the manifold and have it machined.This is the only way to make sure it seals.IF this doesn't cure the issue,then the problem is something really obvious.

[nismosilvia]

Datsmike I'm fixing up a 78 810.

[72240z]

If you want/need new cvs axles or a dif for that 810let me know :-)

[datzenmike]

Datsmike I'm fixing up a 78 810.

 

Saw this and assumed.

• Location:Lake County Ca
  
• Cars:2002 Tacoma, 240sx
  

 

At first I was thinking it could be a hole in your ERG tube but was thinking this might be a 240z motor which didn't have it. An 810 changes this as they did have EGR. This is worth checking out as the EGR tube directly connects your exhaust manifold to the intake where the EGR valve is located. These tubes are stainless steel? something? but they do corrode away and can leak. This tube and EGR valve is located at the very back of the motor and would be a suspect place for smoke to get out from the exhaust manifold.

[nismosilvia]

I very loosely attached the egr tube back together, and Im thinking that was where most of in not all of the smoke was comming out. Should I put some teflone tape around the studs to make it extra leak proof? I also rechecked the gasket area where the manifold and muffler attached as one side looked raised compared to the other and got the flange as straight and level as possible. At this point ive checked all the smog stuff and everything checks out, the car doesnt smoke at all while idiling and running, just when seafoams added. Im going to smog it next week, hope it passes I just wanna drive this car bad before the rain comes. Ive got my eyes set on a rearend from a 280zx turbo at the jy near me, but thats down the line seeing as I dong know if it will smog.

 

Check the metal tube pipe fittings at each end are tight and the pipe isn't rotted away. I doubt Teflon will stand the heat.

[72240z]

Use high temp rtv(red) on the egr.

[Z-train]

Sounds like the leak is still there and the Seafoam just makes it visable.Ultra copper would be a better choice.Let it cure over night before firing the car.

[72240z]

Either works fine, red is good to 650F and copper is good to 700F. I dont use the copper unless its actually needed because it usually costs more.