clkinaz

Hi all,

I've got a 94 truck with the 3VZE and during the inevitable head replacement tear-down, I noticed what seems to be an inordinate amount of "gunk" in the intake plenum and especially on the EGR valve tube.

The truck runs fine. (Well, it did run fine right up until it didn't) but there was little or no indication of problem (head gasket failure aside). I cleaned it a little but decided to bolt it back together as-is. Some folks suggest I simply need a new PCV valve or maybe service the EGR. One buddy told me I just need to skip the cheap gas and start running Chevron Supreme.

Suggestions?

I've been following the head gasket replacement threads religiously and have found this site to be a great help! I should be turning the key today or very soon.

Charles

justin_4runner

don't run the cheaper gas, u can still go with 87oct but get it from shell or chevron. the stuff from ampm and safeway are watered down a little and u will need to change out your fuel filter more. or at least should. yes i would replace the pvc valve and see what u can do about just spraying carb cleaner threw it to help cleaning it up a little, i have the same motor and just rebuilt mine. what an experience that was but one more thing i can now say i can and will do again.

vasinvictor

iTrader: (3)

Gunk in intake is normal. If it's oil in the plenum, you may need to replace PCV. Just see if air sucks thru it but shouldn't allow to be blown thru it. Also if you shake it and it rattles, it's generally good. The gunk you see is probably from EGR (exhaust gas recirculating valve) that spits exhaust back into intake at part throttle cruising to reduce combustion temps. Also, replace that knock sensor wire before buttoning it all back together.

vasinvictor

iTrader: (3)

Also I use only 87 octane ethanol free gas, no matter the brand. Never had problems in the yota with any brand or any grade- ever.

aa1911

iTrader: (1)

completely normal (and annoying....) it's due to the ever awesome EGR system. you can block it off but not the recommended technique depending on who you ask. just clean it every so often, it is a PITA to remove all 50 vacuum lines but I took about a quart's worth of crud out of mine at 162k, used an entire can of TB cleaner...

as for fuel, the engine is designed to run on 87 supposedly, I've been running 92 for a couple years now with no issue, good mileage. I try and stick with Shell gas as much as possible, ethanol sucks too..... shouldn't make any difference on the gunk build-up though...

Wrenchinjoe

X2

If you already have your plenum off, you can turn it up on end (throttle body pointing up) and spray TB cleaner down through the EGR passage. Be careful not to spray the small passages in the throttle body, but if you insert the long skinny nozzle of the TB cleaner well past the throttle body you can spray out the EGR passage safely. Just clean the perforated EGR tube with TB cleaner and a brush. Cleaning this gunk out made my engine idle much more smoothly.

aa1911

iTrader: (1)

yes, I had a weird idle problem also a while back and pulled the plenum and TB and cleaned it/ changed PCV valve, checked my vacuum lines etc... still stumbled at idle when it was warm. I pulled the TB off again and cleaned it once more,still problems... then the 3rd time I yoinked the TB, I noticed the bypass port around the butterfly plate had some crud in it still and once I got all of it out, idle problem went away completely, smooth as can be now. she just needs some lovin' now and again...

I would also worry about all that gunk in the plenum breaking free and ruining the engine but doesn't seem to happen...

I have alcohol/water injection on it also now and that helps keep things clean all the way thru. some folks even use dH2O into a vacuum line periodically to knock crap out but that's the most dangerous course of action, potential for knocking a large chunk loose supposedly. Seafoam also is great stuff!