Engine knock

[Cluett]

I have a 99 Durango with a 5.9 engine and some times when I am at a stop light I can hear a slight knocking and it sounds like it is coming from the engine. It goes away when you start moving again.I have replaced the intake manifold gasket, and yes it was busted. Got some smooth hp back but still have the slight knock sometimes when idling.I run 93 octane gas ??? If anyone has some information on a possible cause please let me know. If not I will have to suspect my motor will need some major work.

[mprtech]

Usually if its a rod knock it will knock on decel. Rev the motor up to 2k then let it snap shut. If you have a rod knock it will knock while the rpms come back down. I would check your belt tensioner also.

[Cluett]

Originally Posted by mprtech

Usually if its a rod knock it will knock on decel. Rev the motor up to 2k then let it snap shut. If you have a rod knock it will knock while the rpms come back down. I would check your belt tensioner also.

I have reved it up and heard nothing. I don't understand how the belt tensioner whould have anything to do with it, but when I replaced the intake gasket I noticed the tensioner was very stiff. I will pull it off as soon as I get a chance,and free it up or replace it. I find it funny that you only hear it at idl, and not all the time. You can't hear it outside the vehicle.

[tommychau]

I have a 2000 Durango with a 5.9. I also hear the faint knock sometimes, mainly when the engine is cold. After warm ups, the knock sometimes go away. It sounds more like a thumping knock. Almost sound like a smog pump or something. The dealer heard it also and spend an entire day looking for it and cannot find it. What sux was they had to call a dodge engine specialist to check it out and after that call was made, the noise went away! haha. Always the case this way!

At idle, the noise is barely audible. But when I rev and hold it between 1200-1400 rpms, you can hear the faint thumping knock. Sounds like a air pump pumping air or something. That's the best description I can make on that thumping noise.

[mprtech]

The tensioners commonly make a clicking or clunking noise at idle. If it does not move freely when you pull on the belt then it is shot. Give it a try.

[Cluett]

I was referred to a mechanic that had allot of expertise in troubleshooting engine noises and problems, when he heard it inside the Durango he got out and looked in the engine compartment to the firewall and put his hand on the evac solenoid that is attached to the top part of the firewall. He said is fairly common in a lot of Chrysler products to have loud solenoid valve. He also said if it were your engine you would here it outside the truck. He said if I were to get a new one, it would most likely start doing it again with in 6 months. So all is well and I hope this info helps someone.

[surfdade]

I have a 2000 dodge durango that I have been noticing aknock from what I think is coming from the engine. Here the deal, everytime I accelerate up a hill I get some kind of knocking soung in the engine compartment this usually happens when the rpms are at around 3000. I have tires multiple remedies but to no avail. I have been using 89 to 92 grade octane. I did use the low grade octane about 2 months and ever since I have noticed the knock. Can any one offer any help

[Cluett]

You might want to take a look at the possibility your intake gasket is bad. I had to replace mine, becuase it did the same thing. If you go throu some oil on a long trip, and never see smoke, and can't seem find out were it is going, the chances are your intake gasket is bad. The oil mixing with the gas tends to lower the octain rating, resulting in pinging or knocking when accelerating. It is the gasket on the bottom of the plenum ( the aluminum intake ). I found the outher gaskets were fine, but you will need to replace them anyway to fix the plenum gasket. If for some reason you don't think this is the problem get a mechanic listen to your engin. It is very important to get the right mechanic to listen. I would try looking for a reputable performance shop that specializes in engins. I found thay are very helpfull and knowlegable. I hope this helps.