Smoking from Under Hood
 

Getting close to buying. BUT after about a fifteen-minute highway drive this afternoon, some smoke appeared from under the hood. Not heavy at all, it appeared from the passenger side of the engine, coming from extremely low and towards the front of the engine compartment-- almost like it was coming off the front of the engine itself, or possibly the manifold, but I could not see any signs of oil leakage.

The current owner warned me about this and says it does this from time to time. Engine temp. and oil pressure were normal during the test drive.

No smoke in exhaust.

Any thoughts on what this might be are appreciated. It seems like a good car at an extremely cheap price -- but the smoke concerned me enough to keep from buying it today.

What color was it? Also what year was it? TII or N/A? The 86-88 had a really FPD (Fuel Pulsation Dampner) that leaked badly over time when the diaphram fell apart. This is known to cause more engine fires than one could count. Also, check for wear on the oil cooler lines, as they have a tendency to go bad over time. Are there any error codes on the ECU? I would just have it looked over at a Mazda dealer to be sure everything is in order.

It's an '88 GXL, N/A. Smoke appeared white; did NOT smell like gas. It had practically no odor at all.

Check his coolant overflow tank. If it is too full, then the escaping water/coolant from the tank while the cooling system is hot could be hitting something and causing steam. Did it dissipate like steam or it was clearly smoke?

Thanks, fc3s.org. It was clearly smoke, though, and not steam. I originally wrote "dirty white" as the color, and that seemed too vague. But "dirty white" really is a good description. It wasn't blue smoke, but not puffy-white either!

To elaborate, it just smelled like, well, a hot car. The smell reminded me of an car I drove in college which leaked oil over all six of its cylinders -- that *kind* of smell.

But I couldn't see any evidence of oil on this RX-7's engine, although there was some grease and grime here and there, about what I would expect on a car with 125,000 miles.

Hmmm, truely weird there. I would take it to a dealer to make sure nothing invisible is wrong with it. There may be a hidden reason it is so cheap. Better safe than sorry. Let me know what it is if you find it!

Thanks again, fc3s.org. Problem is, I'm in the middle of Iowa right now and don't have a dealer or mechanic I trust -- it was just chance I ran across this car for sale at all. The price has gone from $1500 to $500 in the past month -- current owner is retired and doesn't like it because it floods on him once in a while when he's making multiple stops while running errands. He's had a hard time selling it in rural Jasper County, Iowa, because people tend to go pale when they see nearly 130,000 on an odometer.

It actually runs good, idles when warm about 550 - 600 RPM and very smoothly, so I was prepared to buy until I saw the smoke.

Oh my. I have this exact problem with my '86 GXL N/A! I drove the car really hard the other day several times while testing out my new fuel computer, and it started to smoke on me, in the exact same place, and it was a darker "dirty white". I immediately jumped out and popped the hood to see if I could figure out where it was coming from, but most was escaping from the wheel well!! It didn't seem to be coming from anywhere near the engine block, and it was gone before I started inspecting the front of the car! And it only happens once in a long while: both times though it's been when I've driven the car hard for a long period of time...

I wish I knew what the problem was though!!

For $500, I'd bring it home and get it checked by somebody I trusted. If it turned out to be something major, you could sell it for the same amount, or even part it out. But if the body is in good condition, than that alone would be worth the $500.

If I had to guess, I'd check for leakage from the radiator hoses, perhaps up near the thermostat.

Just my $.02

I had a very similar problem. My thermostat gasket started leaking coolant, and dumped a whole bunch all over the engine. After it dried, (white) smoke was still coming from the exhaust manifold area for a couple days. Turns out it was coolant in the manifold box. I hosed it down for a while, and let the engine burn off the water - it was fine after that (and fixing the gasket!). Let me tell you, I was going crazy trying to figure out what it was.

For you, try to find any coolant leaks - it could be simple like mine, or something like a cracked block - which is detrimental.

It's definitely NOT coming from the block, and I believe that Mark.Hallam and I are having the same problem. I just replaced my thermostat and gasket about 4 days ago, and that isn't the problem. The smoke isn't coming from anywhere near the block, but on the furthermost passenger side of the engine bay... something over there isn't working correctly, but my block is fine. I had a compression test done on both rotors a month ago [and I had seen this problem before then], and had my emissions tested for coolant and and oil, and it passed with flying colours.

I don't think I'm ever going to find out what it is.

Can anyone help out with this???

Ok... first... if it runs ok, for $500, I would buy it. Check for coolant leaks- and pull off the cap on the thermostat housing, start the car, and see if it pumps out coolant. If so, bad.

REPLACE the pulsation damper. Don't even try to check it- just replace it. If it's bad, you WILL have a fire, and it WILL be expensive to fix.

I don't know about the smoke issue... but it may be PD related.

Brad

if the smoke is comming out of the wheel well it could be a small brake fluid leak.

Re: Smoking from Under Hood
 

That is near where the oil-cooler is. maybe that is where the problem is!

Marco.