Hello to all, I went to clean the throttle valve on my 1996 Dodge Ram today. It has the 360 V8 magnum. Along the way I dropped a plastic piece into the manifold so I had to remove the throttle valve. I then smelt gas and looked into the manifold. It had stale gas sitting in it and the manifold was all sludged up. Any ideas?

 

Go to the top of the page and read all about Plenum gasket repairs. You MOST LIKELY have a blown plenum gasket. To fix it RIGHT you need to go to Hughes Engines and get a plenum gasket repair kit. It will fix your problem plus you'll get some MPG back and power too.

 

I'm having a bit of trouble trying to figure out how a blown plenum gasket would cause a buildup of old gas in the void of the intake. The vacuum of the engine sucks oil into that void, which in turn burns it with the air and fuel coming down the throttle body.

If there is unburnt fuel in the intake, I would think the engine is somehow not running as efficient as it should. Maybe a rich condition, maybe a failed ignition...

...true, the plenum gasket may be blown, and may need to be replaced, but that wouldn't really cause a pool of fuel in the intake in a way that I could say they were directly related.

 

I've smelled that smell too many times and rest assured a blown belly pan gasket is the cause. Save yourself some money on the aluminum belly pan and get this one off ebay. http://www.ebay.com/itm/DODGE-JEEP-A...229d9f&vxp=mtr As good or better than the Hughes. The seller is a forum member here...1999blkdakrt (Brian).

 

A blown plenum gasket can cause a loss of vacuum in the cylinder, which can then force the air/fuel mix to settle into the intake as there can be negative air flow(reversing the normal direction) back into the intake. So it may well be indicative of a blown plenum gasket.

 

my crystal ball reads:

blown plenum gasket.. responsible for clogged cat.. responsible for cracked valve seats.. responsible for burnt valve.. responsible for reversing vacuum back up runners into plenum/intake.. responsible for pooled and stale gas in corners..

my crystal ball rocks, y'all..

 

Again, plenum may be bad and probably needs to be fixed, but all of that stuff can happen...cracked valve seat, burnt valve, reverse vacuum, pooled stale gas...can happen even if the plenum gasket was fine.

I swear everyone's so plenum jumpy it's scary. I just installed new shocks a month ago, and they've already started thumping and rattling. Their dead already and I'm sure someone would have blamed the plenum gasket in the truck's engine given the opportunity to post it. Geesh.

 

i'm thinking this was the indicator most went with to figure the lower gasket is busted..

 

You asked for ideas and we've given them to you. Now whether you want to take our advice or you think we're all crazy is up to you. Good luck with the fix!!

 

Who asked for ideas? I'm not the original poster.

The plenum gasket suggestion is a good idea, but for the original poster's question, it solves nothing but possibly the root of a chain of events that may have led to the condition he's experiencing, which is unburnt fuel in the intake.

Okay, so someone suggests to him, fix the plenum gasket and all will be well. BS. The gasket won't leak anymore but he's still driving around with a rich condition. Maybe he still has a cracked guide. A burnt valve. Those things don't get fixed or even diagnosed by changing the plenum gasket.

In effect, telling him it's the plenum gasket means he'll have to tear open the engine twice. Once to fix the plenum gasket, and again to pull the heads for rebuild.

I would rather someone suggest, hey, do a leak down test and a compression test. Suggest, pull the heads and have them rebuilt and checked...and WHILE YOU'RE IN THERE, fix the plenum gasket, which is no doubt leaking and causing problems.