motor experts... any suggestions?
 

I have a 90' LS and I have been getting some white smoke out my pipes every now and then when I crank my car up. Also I get slight hesitation and jerking during idle but nothing during acceleration. Do you think its a burnt valve? I also noticed that after a month, my oil is black like my motor is burning the hell out of it..... any suggestions?

Your oil turning black is normal, it doesn't stay clear throughout it's whole life.

White smoke could be a blown headgasket. But you say it's "every now and then" which leads me to believe it's just condensation in the exhaust system, which is also normal.

This is a true statement, but should not be the case after a MONTH of having it changed.

Calyko,, need a little more info on symptoms. When was the last tune up on the car? Hesitation and jerking at idle, sounds like it is not getting enough air at idle. Could be a bad MAF sensor. As far as the premature blackening of the oil, could be various seals on the engine worn out, causing you to burn it faster.

Also a very true statement, however blown headgaskets on these engines are rare; it can happen but is rare.

Calyko, are you losing power steering fluid? White smoke on Startup, is a common symptom on our cars that you have a power steering leak and it is getting in the manifold to be burned off. Check up in the sticky section in the Power steering bible for more info.

I saw that sticky on the Power Steering bible and checked mine out and it is fine, Im not losing and fluid there. Hasnt been that long since my last tune up maybe 6 months. I just changed my spark plugs maybe 2 months ago and my wires just before that so as far as tune ups im there. This all started when I had to change my started out and I believe I got some of my hoses crossed on re-assymbly. I think that I burnt either a valve or a ring when I crossed thoes hoses up.

Oh yea cleaned and changed my MAF and filter so they are good too...

i wouldnt worry about a burnt valve or bad/stuck/broken ring. These engines are pretty tough.

I'd bypass that P/S idle up valve and try it for a few weeks, there could be a slight leak there that is hard to spot?

Like he said :thumbup: It's not very likely a valve in the head, or anything else has been damaged. The power steering valve is such a common cause of white smoke, and it's the most likely candidate. I had the same issues, smoke and not seeming to be loosing PS fluid. At the time, I felt it was major engine damage or wear, (My engine was just shy of 200K miles) but In the end, I was thankfully relived that it was just the P/S valve. :woot:

Look white smoke is coolant, blue is oil. Alot of the time these two are hard to distinguish between. Especially if it is only manifesting itself at start up. I would say that it sounds like you have a "cold" coolant to cylinder leak somewhere. Very possibly a head gasket. You need to run a block test, or have someone run one. This will tell you if you have exhaust gasses in the cooling system.

Some of these small, specific condition, coolant to cylinder problems are hard to verify in a technical manner.

Hope this helps...

Another very good point, but these 2 fluids also have a very distictive smell that goes along with them, that you really can't miss. With the symptoms that he is describing, as well as the fact that the PS leaking is a very common ailment with our cars (which also produces white smoke on start up), it most likely is this which he is having problems with. Start with the simple, small, more accessible stuff first before tearing open the engine and getting into some heavy mechanical work.

I have been losing coolant like crazy lately...maybe that is it.

Check your oil dipstick. Is your coolant mixing with your oil? When you pull the stick the fluid will look kinda milky white in color. If this is the case, you may very well have a blown head gasket, even tho this is a rare occurrence, it can happen. As jhill suggested, have someone run a block test to determine where the leak is. Worst case scenario, and I do mean the absolute worse case, could be a cracked block.

Get your cooling system pressure checked. If should hold a considerable amount of PSI. I just reassembled my 1UZ and it held 17psi for 30 minutes. If you have the tool it very easy, otherwise bring it to a local independent shop and they should be able to take care of you for cheap, maybe you have a buddy with the tool? Can you smell the coolant being burned in the engine bay? No abnormal smoke in the engine bay itself? It's very really a coincidence that you did something, and now there is a problem. Just carefully think about everything that could have happened. Maybe pull off the air intake, and check the throttle body for oil. How do the spark plugs look?

There is a smell but its more like my engine burning oil, no smoke from the engine bay... this is the background story....

Did a DIY on the starter and alternator, when I re-ran my hoses I crossed some of them up... took it to Lexus and they said I was pumpin coolant into the engine. Got that fixed....

I did think about my plugs, checked them, burned out...swap out lol. still having the issue....

Now it seems like I'm having to replace coolant every other day but I dont notice a leak under the car...no noticeable leaks in the engine bay either... I did clean my throttle body when I put my manifold back on...

This is soooooo crazy... the only thing I can think of is this one harness that is not connected to anything on the driver side of the motor, probably 2 or 3 fuel injectors down(pic will come later)... I think it may be that but for the love of all that is great I cant figure out where the hell it plugs into

Suffering the same mysterious disappearing coolant thing here, with no noticeable leaks. Annoying, isn't it?

Gents, pressure check your system, for like the 3rd time. Does it hold pressure or not? Your problems wont solve themselves, you needs to start doing some proper diagnosing. Are you guys properly filling it, maybe your trapping air in there.

In my case, yes, hence the query, as per correct procedure - however, I have discovered - and I do not know how I missed it, that coolant is collecting on the tray underneath! Doh doh doh!!