Surging

[MikeyB]

I have an '01 2500 HD Duramax with 42,000 trouble free miles until now. At idle the engine surges. It is not noticeable on the tach but the oil pressure moves slightly with each surge of the engine and you can definitely hear it. I replaced the fuel filter about 4,000 miles ago but will try that first as far as troubleshooting goes. I seem to remember something about reprogramming or the fuel pressure regulator maybe being the culprit. I'm just hoping it is not the dreaded injector problem. Any info or suggestions?

Thanks,
Mike

[Mark Rinker]

Try searching this forum on 'idle surge'. I think you'll find that most point to the fuel pressure regulator. Could be as simple as needing some fuel additive to free up sticking injector(s).

If your 2001 injectors are still stock OEM, it might not be the worst thing to get them replaced under warranty anyway. If the new fuel filter and a few tanks of fuel with FPPF or similar quality additive doesn't clear it up, get it to a dealer.

If you see any signs of 'making oil' on the dipstick, or even traces of white smoke at the exhaust, get all 8 injectors done - pronto.

[crafty]

Mine is in the shop right now having the third injector replaced. My key symptom was a surge at idle or uneven idle. The dealer says that since I have no smoke or sign of fuel in the oil I do not qualify for having all eight injectors done but they will do the one and only charge me the $100 deductable.
Each time this has happened the balance rate has been out of spec for one cylinder only. I think the reading this time was a plus 6 on the number 6 injector.
I suggest that you have the balance rates checked first before you replace anything. It only takes a few minutes and then you will know for sure.

[Dakster]

Crafty,

Do they charge you the $100 deductible each time? So if they will only replace 1 at a time you keep having to fork out the $100. Doesn't quite seem fair... But then again, what is?

[MikeC]

Crafty,

Do a search here, my bet is you should not have to pay for a recall item. May be wrong, hopefully others chime in.

Mike

[DmaxMaverick]

Crafty,

Do they charge you the $100 deductible each time? So if they will only replace 1 at a time you keep having to fork out the $100. Doesn't quite seem fair... But then again, what is?

The bulletin specifically states "at no cost to customer". Now, if the dealer were to replace the injectors under the 100K engine warranty, the $100 deductible would apply. If so, the dealer isn't abiding the special policy, and taking these matters into his own hands. Doesn't make sense. They should not be replacing them 1 at a time on an LB7, unless the warranty terms have expired. Even so, the cost of the individual injectors is minimal compared to the dealer's shop rate for getting to them. Once one is accessed, the rest on that bank are easy and quick. I had 2 injectors replaced (at the same time, on the same bank) prior to the special policy bulletin, and I wasn't charged the deductible. That was about 45K, past the B2B warranty. The more I hear, the more I like my dealer.....

[crafty]

This is the third injector in 5 years that has been done and the first one that I've been asked to pay for.
I gave him the special policy number that was mentioned here and apparently I do not fit the criteria. In the interest of "Good Will" they are doing the replacement anyway but charging me the $100 deductable.
They supposedly ran a bunch of tests and I do not have the excess fuel return or the leaking or the smoking that are all part of the policy. All I have is a balance rate that is out of spec. on the number six injector (it reads a +6) and that is causing the idle to be uneven and the engine knocks when starting up in first or second. The mileage is still around 19 to 20 mpg and there are no other problems that I'm aware of.
This service department has always treated me well so far. Last time I even got a rental car and I was out of the warranty period then too. This time I had to get their shuttle service to drive me home (30 miles one way) and I will get them to pick me up. That will make up for a bit of the cost I have to pay.
I have 126300 kms on the truck and it will be 7 years in December since I got it. I plan to work it hard the next few months with some towing and trips so maybe the remaining injectors will fail before the "good will" of the dealer or GM runs out.

[Duramaster]

Do you ever add any "STANADYNE" diesel fuel additive to your fuel tank?

[crafty]

Duramaster,

Yes I started using fuel conditioner two winters ago when I had the fuel freeze up on me one cold morning. There were four or five guys that had that trouble the same morning and we all buy fuel from the same place so we knew then that the fuel supplier didn't winterize the fuel to a low enough temperature.
As a rule I don't use it the rest of the year though. I can't recall the exact name of the stuff right now but I buy from a major heavy truck repair shop.
I picked it up from the dealer on Friday and it certianly runs much better than before. I'm off to Ottawa next week so it will have a good 3 hour highway run eah way with that trip.
Do you have any idea what causes the balance rate to go out of range? Are the injector tips still suffering from excessive wear or is it something else? I just hope that I don't have to pay for the other 5 to be done before I sell the truck. I plan to keep this another seven or eight years if I can. My old 6.2 went 15 years and never had a wrench put on it. No injectors, no clutch no injection pump. That was a great truck. It just lacked the power I needed.