PickupStix

Hi all.

I have a 1992 Lexus LS400 I've been driving for over a year and have had to deal with this issue for the past couple of days. I'd figure I'd run it by you guys to see what sort of problems this might be a sign of.

So yesterday (Sunday) I was doing my usual city driving and decided to pump the car up a notch and floored it - however, instead of the usual acceleration I got from my car, it sounded like the car was trying really hard to speed up.

I had this problem with my old beater '92 Camry and I dealt with it until the repairs necessary for the thing required me to scrap it.

I noticed the car started to run rough, and the idle on it was a bit rougher than usual. I also noticed when I idled very faint white smoke was coming from under the hood. Not a lot (I know what a major coolant leak looks like as one of the hoses in my old Camry ruptured before) but it was pretty obvious it was either water or coolant.

Checked my fluids - coolant was at half, but I haven't refilled that in awhile so I poured some in anyway. Also threw in a quart and a half of engine oil to be sure.

Google says it's a blown or cracked head gasket and that it may be a possible internal issue, but I'm not having any overheating problems - temps are stable. Called an experienced mechanic in the area and he also thinks it's possibly something else leaking, as he said I'd have white smoke coming out my tailpipe if the head gasket was blown. Unfortunately, that mechanic is in extremely high demand and can't see me until next month.

I'm not terribly mechanically inclined for auto stuff, so I don't think there's much I can do at the moment, but I want to run it by you all to see what you think. I really hope it ain't the head gasket as I'm a paycheck to paycheck kinda guy, but if it is I'll probably have to trade up to something newer. Sucks too, as I love this car.

Your help would be greatly appreciated!

steve2006

Check the driver's side coil pack these are known to fail due to heat from the engine it's located opposite the battery tray mounted on the engine block.
You've already replaced the capacitors in the ECU of course

dicer

Also check out evap system. So what does the white smoke smell like? Gas smell ? Oil smell? Antifreeze smell?

KJG92

Don't know if this can happen on these cars but one time on my old 79 Z28 the trans modulator valve went bad and was sucking transmission fluid up to the intake and burning it. Trans fluid burns white.

PickupStix

No, I haven't actually. I'm not sure if it was replaced before and I don't have electrical experience to replace the capacitors myself. Is this a common problem?

I'll check the coil pack - wouldn't a failed coil pack also cause my temps to rise? My temps are checking out okay.

It smells kinda like - well - steamed water? Kinda musky. This used to be my dad's car and he's insistent on simply using water for coolant, and I'm assuming that isn't a great idea but it's what I've been using for the past year. I'm assuming that smell is the leaky water evaporating off as it hits something hot.

I just did a brief 10-15 minute drive from my workplace to my house for lunch - no smoke smell but I still kinda smell that steamy smell. Car is definitely low on engine power - I have the accelerator almost level with the floor and I'm hardly able to accelerate.

I'm thinking of going to another mechanic earlier to try to have them take a look but I want to make sure I have my bases covered before they do. The really good one is booked for this entire month so I'd have to wait until next month for them to look at the car. I just want to avoid any further damage to the innards before I get there.

cobalt91

How many miles is on it? Just water is not a good idea. The anti freeze helps with more than cold Temps outside.

dicer

Antifreeze is formulated to be a protectant to the metals, plain water everything will corrode and that can help develop leaks. It could be something leaking, it could be the ecu, there are a lot of it could be's. With out seeing it we are pretty much helpless. A radiator could have a leak around the tank, I have one and it just weeps, but that doesn't explain power loss. Does the exhaust have any smoke? Did you open the hood and look for where the smoke was coming from?

RA40

iTrader: (6)

Many possibilities. Is the coolant a clearish red? What is the color of the engine oil? At this stage in their lifespan these cars can accept lots of maintenance.

PickupStix

250k or so.

Since I use water, the coolant is kinda clear, but not red. Engine oil from the dipstick seems to be brownish.

No smoke from exhaust, and most of the time I don't see smoke from under the hood. When I noticed this problem, I saw smoke from under the hood on the driver side when I parked and then after that I saw some from the passenger side, but now when I flip open the hood with the engine running I don't see anything. No overheating issues either.

I'll get the coolant system flushed and change it with actual coolant. I guess the part for me that puzzles me is the lack of anything from the dashboard telling me what's wrong or the temp gauge.

About the ECU - are you guys saying it might possibly be the ECU too? Just searched the rest of the forum - I'm guessing there's no way to tell unless I actually get to the ECU and check if the caps on it are leaking, huh?