Smoke in engine bay after highway driving

Hi all,

New Tacoma owner here (1997 regular cab 4x4)

I've noticed after 30+ minutes of highway driving I get a minute or so of a burning rubber smell and then when I'm off the highway there's a small amount of smoke on the passenger side of the engine bay.

My ac hasn't worked since I bought the truck, could that be a factor? Smoke happens regardless of ac being on or off.

There is a small amount of oil seeping in the area, and potentially pooling on a sheet metal cover of some sort (haven't been able to find a diagram that names the part) so I'll try and get some pictures up soon.

Any help is appreciated, thanks!

Edit: I've attached a picture of the sheet metal thing/cover I was talking about (not the skid plate) you can see a small spot of oil on it.

 

if your ac compressor is seized, and the ac clutch is engaged, it could be your ac belt burning up. that'd be my first guess.

is the sheet metal your skid plate?

 

Well,

oil, + smoke + ac not working

That's a pretty good sign that's at least part of the problem. Find the oil leak, fix it. Also check that your ac pump is working properly (hint, it probably isn't!)

What kind of oil is it? Engine oil, or maybe fluid from the ac pump, or other??

 

Would the ac belt be an issue if ac is never on?

I'm not sure what type of oil it is or where it's coming from, I'm new to Tacomas. I've done some less intense repair work in the past (drum brake rebuilds, axle shaft change, etc) but don't really know my way around this motor. It's the 2.7, forgot to mention that. I also haven't noticed any oil lost from the dipstick reading, and there are no puddles underneath the truck after sitting overnight.

 

ac belt could be an issue even with the ac off if something is seized. if you have the truck running, take a look to see if things are spinning or not. also compare the ac belt to the others, see if it looks more worn.

the oil could be lubricant for the ac (which, if it's now all over your engine compartment would lend support to the seized ac compressor theory), or it could be another fluid altogether. which could be smoking if it's getting on hot engine components. if the ac is a red-herring, then there are lots of other possibilities.

without more info, it's hard to narrow it down any further at the moment.

 

Alright, I'll take a look and report back. Thanks for the response!

All the belts were new when I purchased the truck in September, so maybe the wear will be obvious. I've seen a few numbers thrown around for a new ac compressor install and they're over a grand, is there a cheaper fix if it is the culprit?

 

ouch. i'm not sure of the exact process for your motor, but have to assume it's close to that for a 3.4 if you're handy you could do it yourself except for the discharging (and probably re-charging) of the system. You'd have to look around for some guidance on the exact steps, and what else you may want to replace while you have it apart. if that's not an option, make sure your windows go up and down i guess...

I'll be replacing my non-functioning ac compressor at some point, but it's not super high on my to-do list at the moment.

 

My 97 would smoke from under the hood also after about 20 minutes on the road also. Come to find out the valve cover bolts were all loose and leaking oil onto the exhaust manifold. I tightened them back up and was good to go. Don't know why every valve bolt was loose though. vibration over time.

 

All pulleys are rotating, the belts all look fine. However, from underneath the truck I can see much more oil on the passenger side of the engine, its seeping much more than I thought... still no change in dipstick reading though.

Do you have a picture of where these are located? Worth a try I guess

 

assuming your engine is the 3.4 here is the picture of where the bolts will be. on each side of the engine.

 

The sheet metal is a heat shroud for the exhaust. Shit's around areas of the exhaust system that channels heat to keep components from being fried, and thrives on slicing skin when you're not careful.

 

Get some engine de-greaser and spray around the engine bay really good. Find something like an old tooth brush and scrub some of the oily areas. Rinse of with the garden hose. Check all the valve cover bolts. Make sure they are snug, don't get to strong arm on them. This could help find out what's going on. You might pull over every 10-15 minutes of driving and start looking around.

 

He said its a 2.7

 

Alright, thanks for the advice. I'll try and take care of this sometime this weekend and post back with results.

 

If the smoke or burning u would know if it were belts as it has a rubber burning smell, it's probably ur valve covers .

 

Well, before I had a chance to investigate further, the truck died on me while on the highway. Felt a sudden loss of power, when I pulled to the shoulder the engine cut out. There was smoke coming out of the heat shroud around the exhaust. Motor would start but sounded absolutely horrible - all kinds of knocks and weird noises.

The tow truck driver said that sounded like its something to do with the fuel system, maybe the pump or filter? Seemed to think the engine wasn't getting enough gas.

I had an old jeep xj that died at highway speed in a similar fashion, ended up being the throttle position sensor - could that be a culprit?

The truck is at a mechanics now, waiting to hear from them sometime today.

 

ouch. sorry to hear OP!

 

Thanks.

I'm in contact with the dealer I bought the truck from, hopefully once the shop diagnoses the issue(s) they'll be willing to work with me on a fix.

 

Well I just heard from the garage... I need a new engine.

 

ouch. Not the news you wanted to hear.