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Smoke from engine area when driving in 4wd!?

2K views 16 replies 5 participants last post by  rejesterd 
#1 ·
So, new issue now. I had tried engaging 4wd Hi and Lo modes when test driving this Sorento, both modes engaged fine, can hear the transfer case engaging in both modes.

But since I'd read that you shouldn't drive in 4wd with them on tar road, I didn't drive in either mode.

Today I went for a short drive in 4wd hi mode, just at slow speed 30kph in a straight line. Wouldn't have gone 500m before I smelled something cooking. Pulled over and could see smoke cominf from the engine bay. Not thick but noticable, like engine oil burning off a hot engine. Couldn't see where it was coming from under the hood but it seemed to be more to the passenger side of the underside of the engine, could have just been the wind blowing that direction though.

I turned off 4wd Hi and continued on in 2wd, smoke went away immediately.

After I returned home I checked that both 4wd modes are still engaging while stationary. Seems they still engage normally.

Any idea what could be causing this smoke? Obviously something with the front end is getting hot, maybe the transfer case?

As posted in another thread this morning, I'm getting a clunk on stop start which I suspect may be related to the transfer case. So I think the thing might be dry.. I think I will try to drain the fluid soon and replace it.

Any other suggestions would be appreciative though.
 
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#2 ·
Change the gear oil in the transfer case. It costs about $10 and you'll know if there's a problem with it, because the drained oil will have metal shavings in it. If it does, probably time to get rid of it.. not worth fixing imo. Or maybe the gear oil has never been changed? That could certainly cause it to overheat after 16 years.

I wouldn't pay too much attention to the smoke because it might just be condensation that's turning into steam because it's sitting on something very hot. If it only happens when you switch to 4wd, the transfer case is definitely the thing to focus on. Good luck.
 
#5 ·
I should have mentioned that mine in an auto.

I will change the transfer case oil next week when I have some time and see what the oil looks like. Hoping it is just low on oil and that I don't find metal shaving in it =/

I don't think the smoke is steam either, it was a dry day, hadn't rained in a while, and definitely smelled like hot engine oil.. Is it possible that engaging 4wd is causing oil to leak from the transfer case (or somewhere else) on to the exhaust manifold, when it doesn't seem to leak at all in 2wd?

Another aside with this vehicle. I'm getting absolutely terrible fuel economy, like 20l/100km (city driving, but still). I've changed the oil (full synthetic, 5w30), air filter, checked tyre pressure (tyres are road tyres, not all terrains), given the engine a treatment with intake and valve cleaner, still doesn't seem to have helped much. I drive fairly conservatively, not full grandma but not a leadfoot either.

Is it possible that there are issues with the transfer case that would cause bad fuel economy?

I've read some places that these vehicles can try to automatically engage 4wd due to faults in sensors or issues with the transfer case, which might mean the car is actually sometimes running in 4wd mode if this is happening (although the light doesn't come on).

Does the EST version of the BL Sorento do this, or only the TOD?

I've heard that disconnecting the fuse for the transfer case can disable all 4wd capability, rendering it a 2wd only vehicle, but that might help identify any issues going on with the 4wd system. Thoughts?

Thanks for all your advice everyone =)
 
#4 ·
But since I'd read that you shouldn't drive in 4wd with them on tar road, I didn't drive in either mode.

Today I went for a short drive in 4wd hi mode, just at slow speed 30kph in a straight line.
Not advised, no. However, I used to drive mine in 4Hi on wet Welsh hill roads with no issues. As you have EST (a non-tod) version there is not much in there to cause smoke, unless the internal oil pump has failed and bearings are cooked. By all means change the oil and see what you have. And invest in a magnetic drain plug (now standard replacement from Kia) if not already fitted.

Never heard anyone complain before about clutch and 4wd. (Although the dual mass flywheel is a bit rubbish and can be replaced with a standard type assembly if you look around).
 
#9 ·
If you smelled burnt oil and it happened after switching to 4wd, I'd say that's the gear oil.

Regarding the poor gas mileage, check your brakes. You might have a siezed pad or a caliper piston has rusted to the point where it's constantly applying some braking pressure.
 
#10 ·
By gear oil, do you mean transfer case oil?

I thought it could be the brakes as well, so I have serviced the brakes recently. The rear calipers were a bit tight initially and hard to press out, but I think they are OK now. Maybe I'll take another look at them. The rear pads are due to be replaced soon anyway.
 
#13 ·
Yeah, the gear oil is in the transfer case and the rear differential. I would change both if they've never been changed. Then see where you're at.

If the calipers were hard to press, that means they're rusting out and they're going to get worse. It might not be your efficiency issue, but if they're hard to move like that, I would replace them soon.
 
#11 ·
What kind of mileage did you get on short trips with lots of stop-start driving?

I'm yet to take it on a long trip of highway driving, so I couldn't say yet what kind of efficiency I'm getting on the highway. But on city streets it is pretty damn bad..
 
#16 ·
Alrighty, so I replaced the rear calipers. The old ones were definitely a lot tighter than I originally thought.

Driving straight after replacing them and the car feels better in general, it doesn't seem to want to 'grab' on take-off.

I also found the source of the smoke when driving in 4wd. I had recently greased the front prop shaft and had left a bit too much external grease in the U joints. When engaging 4wd it must've spun some grease onto the exhaust, causing it to smoke. I've cleaned it off now, so I would assume that is going to fix the issue one the residual grease burns off the exhaust.

I also change the transfer case oil. Although the oil that came out was pretty dark, I put a magnet in the removed oil and found no metal shavings in there, so fingers crossed that means the transfer case is OK!

Now I just need to change the diff oils and the transmission oils. But that is a job for another day..
 
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