Mud in airbox, anything to worry about?

T

tgunnerson

New member
Hey all, just found this forum and it looks like a great community! Having long been a Toyota 4x4 fan (loved my Tacoma TRD but had to let it go last year...) my wife and I just bought a used '05 4runner 4x4. It's definitely a great truck! This weekend I changed the sparkplugs and oil, and pulled open the airbox to take a look at the filter, and found mud residue all on the inside of the box, and even some in the screen that is past the filter. The filter was clean and new, obviously recently replaced. I know you're not supposed to suck water and other junk into the engine, should I be worried about this?

Too add a little more to the story, we were having some transmission problems, I took it to the dealer and they ended up replacing the tranny (under warranty! gotta luv Toyota!) Turns out they found a little mud and silt in the tranny, like it was temporarily submerged. It came in through the breather tube on the top. The mechanic said he checked everything else out and didn't see anything else that looked like it suffered, but now I find this in the airbox and I'm a little worried.

What do y'all think? I've attached a couple pictures. Hard to see, but the red circles are around the mud stains in the screen.

Thanks in advance!
airbox-01.jpg

airbox-02.jpg
 
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It looks to me like some got a little overzealous with a water crossing or wheeling in deep mud. I would have it inspected by a mechanic ASAP. Your tranny going is not a good sign. :(

The engine could be next.

YMMV
 
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Yea, I would have to agree... Take it to a local Toyota mechanic and have them take a look. If water and mud got that far, it must have been pretty well submerged. Can you run a carfax on the VIN and find any info?
 
Since you changed the oil everything is probably okay in the engine. Dirt and such ends up in the engine oil when sucked through the intake. Did you notice any dirt or gritty stuff in the old oil you drained? You may want to consider changing your oil one more time to give yourself some insurance that the engine doesn't have gritty abrasive mud material in the crankcase. I just purchased my '05 about six weeks ago and love it. It was a super clean Hertz car. It may have been beat-on a bit on the road, but was likely never off road and never towed anything. I know that cuz the hitch ball reciever was still new in the box.

Good luck with your sweet new wheels!
 
Dude, that sucks... Sounds like someone was not honest when selling you the vehicle. It was with out a doubt submerged in elbow deep mud, and if there is mud past the filter, all I have to say is Yikes!!! Others have already said it, check the oil! Use a magnet to see if there are any metal shavings/chunks in the oil first, and then look for dirt/sand particles.
 
Thanks for all the input! Unfortunately before I noticed the mud in the airbox, I had already changed the oil and dumped at the friendly neighborhood Autozone.

I suppose I'll change it again and have a look.

It wasn't certified Toyota. I obviously didn't look it over close enough. I noticed a dent in the skidplate but thought, "hey, that's ok, I'll be offroading too..." It was cleaned up soooo nice, not a trace of VISIBLE mud anywhere. Not even in engine compartment. I checked the oil, but not the air filter...

Live and learn I guess.

I still wonder though, the stains on that second air filter aren't TOO big. So not TOO much mud/water got through there. How much does it take to screw up the engine. Probably not TOO much huh?

Thanks again!
 
tgunnerson said:

I still wonder though, the stains on that second air filter aren't TOO big. So not TOO much mud/water got through there. How much does it take to screw up the engine. Probably not TOO much huh?

Thanks again!
Click to expand...

Well check the intake hose all the way up to the throttle body. If there is mud or brown stains that reach the throttle body, then I would be concerned.
 
My experience has been if you get little water sucked into the engine your probably fine. The key here is a "little". If you suck in too much water, the engine can't compress the water like air and causes what's called a hydro lock condition. My son did that on his 90 4Runner and it is very obvious because something has to give. In his case, he bent 3 of the piston rods! The noise was horendous.

Now after the hard learned lesson and his experience rebuilding the engine from the crank up, he is back on the road and taking much better care of his 4Runner. :D

I would just have the compression of the engine checked. If all the cylinders are fairly even then I would say you got lucky and are probably fine.
 
tgunnerson said:

I still wonder though, the stains on that second air filter aren't TOO big. So not TOO much mud/water got through there. How much does it take to screw up the engine. Probably not TOO much huh?

Thanks again!
Click to expand...


All engines ingest some dirt overtime. No filter is 100% effective. Yours may have gotten a large dose at once. Next time you change the oil have it analyzed. Any abnormal wear or other problems can show up in the used oil. ie metals, silica, fuel, etc.
 
I really do appreciate everyone's help here. A few people have mentioned getting the oil analyzed. Where would I go to do this? Do I change the oil myself and bring it to them, or do they change it as well?

Thanks again!
 
tgunnerson said:
I really do appreciate everyone's help here. A few people have mentioned getting the oil analyzed. Where would I go to do this? Do I change the oil myself and bring it to them, or do they change it as well?

Thanks again!
Click to expand...


Some info on oil analysis:

http://www.bobistheoilguy.com/whatisoilanalysis.htm


Get a test kit. Take a sample when you change your oil. Mail in the sample.

http://www.oaitesting.com/

http://www.blackstone-labs.com/index.html
http://www.blackstone-labs.com/free_test_kit.html

http://www.oiltechcorp.com/requestsample.php


Analysis of my truck's oil
 
The one thing I haven't see anyone mention up to now is the fluid in the diffs. If the engine is running okay at this point, it's unlikely it incurred any damage. Especially since the oil was recently changed.
However, if there was damage to the trans because of crud intake, and mud in the air intake, the front and rear differentials as well as the transfer case must have been submerged and the fluids in all of them need to be changed.
 
I got the Carfax before I bought it and everything was perfectly "clean". It's been registered in SoCal it's whole life. I assume it was an overzealous offroading trip that submerged it, but who knows...

Today I called the mechanic at the dealer who replaced the tranny for me. He seemed to think that if there was going to be a problem it would already have happened. It would have been "catastophic" and "immediate failure". I assume this would be too much water and hydrolock. He said a little mud or water wouldn't hurt anything. Still not sure I believe this, but what am I to do anyway. It runs great, it's not like I'm going to swap the motor for fun right now...

As for the diffs, I asked about them when they had the tranny out, he said he checked them and they looked fine and I'd be wasting my money to change them now. Hard to believe this guy works at the dealer huh?

Since the transfer case was completely out I assume it got new fluid when they put it back? Or can it be removed/reinstalled without changing the fluid?
 
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