Posted: Jan 23 2008 at 11:54am | IP Logged

I just had my 99 frontier to the mechanics for a timing belt and tensioner change. It has 265,000mi on it, and the belt has never been changed. Stupid of me, but never the less, an interesting point on how often they must be changed.

Anyway, after the belt change and new plugs, wires, and cap, my nissan had a roughness I experience at only idle speed. After having the tune up checked, everything there is fine.

Here is my input on the rough idle. There is one thing that the truck used to do, but is now not doing since I got it back from the mechanic. Ever since the truck was new, when I would come up to a stop, whether the vehilce was warm or cold, the engine would oscillate back and forth four or five times, high idle then low idle...high idle then low idle... until it finally rested out at normal idle. My old nissan did the same thing, and so I thought this was normal. The truck no longer does this. Just up to the stop light, and poor idle.

Please help!!!

Posted: Jan 23 2008 at 1:34pm | IP Logged

infinitesign wrote:  Ever since the truck was new, when I would come up to a stop, whether the vehilce was warm or cold, the engine would oscillate back and forth four or five times, high idle then low idle...high idle then low idle... until it finally rested out at normal idle. My old nissan did the same thing, and so I thought this was normal. The truck no longer does this. Just up to the stop light, and poor idle.Please help!!!

infinitesign;Your wording has me confused. But I’m not all that swift…

... What engine are we talking about? It sounds like it could be a coolant sensor or low coolant temperature due to a bad thermostat that is fooling with the computer.

It would be nice if our members would add their vehicle information to their signature (similar to mine) plus add their City and State . A member in the same town might be willing to drop by and help you with a problem. Or drink all your beer!

Posted: May 11 2008 at 3:17pm | IP Logged

Phil,

I'm with you here.  Engine grounding kit???  All engines are grounded using a metal grounding strap or two.  One is usually mounted on or near the negative cable from the battery.  Just having a cable come off of the neg terminal and hooking to the engine doesn't ground it to the frame but only gets neg contact to the starter. A seperate small grounding cable usually comes from the neg terminal as well and goes to the frame/fender.  Another strap (somewhat thicker) goes from the back of the block to the firewall. (most cars).

Rough Idle:  Most if not all of these problems can come from these main things:

1.) A vacum hose that has fallen off or that has an opening in it.

2.) The IAC or Idle Air Control Valve has built up some carbon on the place where it seals.  Most dealerships will just clean off this carbon and charge you an arm and a leg.

3.) The EGR Valve is sticking open.  The EGR valve if left open at idle will cause a very rough idle as you need as much vacum as you can at idle.  The only way to check this is to remove the EGR and then blow through it and see if it holds your air back. The air shouldn't pass through the valve unless vacum is applied to the diaphram.

Good Luck.

Mr. Tripp

Augusta, GA