running rough

[enforcer233]

Over the last week or two I have noticed that I thought my emgine was missing, very minor and hardly noticeable. BTW this is a 1997 Suburban with 6.5.

Today I was going to do a piping performance, yes I am a bagpiper, and the apparent miss was much worse, especially when crusing and the engine was not pulling. I also noticed black smoke when accelerating, had not done this before, and light grey/blue smoke at times when crusing.

When I stop the engine reminds me of a gas engine with a couple of cylnders missing or a bad ignition coil. This is not constant and like I said it is worse when at low rpm's or idiling. I also noticed a ticking noise that almost sound's like an exhaust noise.

I looked in the search and from what I have read it sounds like the injectors. The suburban has 110,000 and change on it. I was looking for affirmation of my thoutghts or a different opinion.

Thanks

[twaddle]

Hi there,
It does sound like an injector problem.
I don't known if you work on your own truck or get someone to do the repairs for you?

If you are able to look at the engine yourself, you will need to determine which injector in which cylinder(s) is giving the trouble.
With the engine idling loosen off one injector pipe at the injector at a time and listen for a change in the engine noise and vibration. A rag placed over the injection pipe nut will prevent diesel spraying everywhere but stay clear of the fan belt and fan blades. Retorque each pipe connection after carrying out each test.
If when loosening any of the pipes no change is noticed this is usually the faulty injector. Check all injectors just in case the first one you find to be faulty is not the only faulty one.

If the injectors have a high mileage on them it may be worth while getting them all replaced or overhauled.

As a Scotsman, I hope my advice helps you keep your future bagpiping appointments! hee hee

Good luck

Jim
Formerly Biggar, Scotland
Now residing in Alberta, Canada

[enforcer233]

Listening to the ticking sound again it almost sounds like a compression noise on the drivers side rear of the engine. It also sounds like it is near the bottom of the engine.

I can replace the injectors, probably should anyway, the engine has 110,000 miles, but after listening to this noise again it has me concerned and I will probably speak to my mechanic Monday. He just did a head gasket job for me a couple of months / 1000 miles ago.

[enforcer233]

I have not had the opportunity to do anything witht he suburban yet, but I spoke to my mechanic a couple of days ago and explained to him what she was doing and he advised me that it was the fuel filter and not the injectors. I will advise after I change it if that was the problem or not.

[suburbanK-2500HD]

I have not had the opportunity to do anything witht he suburban yet, but I spoke to my mechanic a couple of days ago and explained to him what she was doing and he advised me that it was the fuel filter and not the injectors. I will advise after I change it if that was the problem or not.

a failing or dirty injector can cause sounds that reminds you of mecanical trouble, like connecting rod wear..

I had a injector that was dirty and i sounded like a nasty knocking sound, and smoke when starting up..

[enforcer233]

I changed the fuel filter and no improvement. My wrench gave me a bottle of TEC2000 injector cleaner and told me to remove the filter again, remove the fuel in the filter housing and fill it with the TEC2000. Did that and still no improvement. Poured the rest of the injector cleaner and 2/3 of a bottle of Diesel Service (white) in the tank, and no good.

I still think it is an injector, but it is hard to tell which one. The only time the truck seems to run right is under full throttle, but she blows black smoke.

I spoke to the wrench today and I will be taking the truck to him in a few days to see what he can find.

[enforcer233]

Money has been kinda tight (paying taxes to IRS, oldest son's wedding, youngest son turning 21 and his birthday party, etc.) and I have not bought replacement injectors yet and I have been limiting my driving of the Burb.

I do have a question though. Is there a special tool or socket for the injectors? I have spoken to another mechanic who has worked on 6.5's in the past (several years ago) and he seemed to think that there was a special socket for them.

I have been looking at the injectors and although I have not tried to remove one yet, I was curious about the nipples on each side of the injector and if a socket would clear them? I know some of you guys would know straight away.

Thanks

[enforcer233]

I do have a question though. Is there a special tool or socket for the injectors? I have spoken to another mechanic who has worked on 6.5's in the past (several years ago) and he seemed to think that there was a special socket for them.

I have been looking at the injectors and although I have not tried to remove one yet, I was curious about the nipples on each side of the injector and if a socket would clear them? I know some of you guys would know straight away.

BUT APPARENTLY NO ONE WANTS TO ANSWER!

Thanks

[DmaxMaverick]

I do have a question though. Is there a special tool or socket for the injectors? I have spoken to another mechanic who has worked on 6.5's in the past (several years ago) and he seemed to think that there was a special socket for them.

I have been looking at the injectors and although I have not tried to remove one yet, I was curious about the nipples on each side of the injector and if a socket would clear them? I know some of you guys would know straight away.

BUT APPARENTLY NO ONE WANTS TO ANSWER!

Thanks

Short answer: Yes.

$30-40 from Snap-On. Considerably less elsewhere. Or, modify your own socket, or make do without.

[joed]

I think I just used a 30mm socket deep enough to clear the nipples. I took a new injector with me to 'test' the socket before buying.

The special injector socket has a hex head on top to allow turning with an end wrench - comes in handy for the #8 injector near the firewall. Easier but not absolutely necessary.

Hope that helps.

Joe.

[enforcer233]

Thanks guys. Please dont take my last post as yellng. I just thougt it was odd that no one had replied, very unusual for this forum.

[enforcer233]

Finally a diesel mechanic had the opportunoty to listen to listen to my burb last week, confirmed that it definately was a bad injector. Fortunately he also had an injector socket to loan. Ordered injectors and return line kit today should be here in a couple of days. Also fortunately I have Thursday to Sunday off to work on my baby.

Since I have never done this before, I wanted to ask, for those of you that have changed the injectors before, did you remove the turbo to get to the injectors on the passenger (right side) of the engine?? Or will I be able to get to them without dong that by removing the rubber fender liner above the upper a arm??

Thanks

[JohnC]

It can be done either way. Which way is better is a religious question...

Rule 1 for injector replacement: Cleanliness is vital. Don't allow the smallest spec of dirt into the system or you'll be doing it again soon...

Rule 2: refer to rule 1...

[enforcer233]

Well after spending most of the day and up till midnight last night working on replacing the injectors in my truck I can honestly say this was a challenge.

But the main news is this -- The truck is no better, still running rough, still has ticking sound, still blowing smoke.

Does anyone have have any other ideas????

Thanks

[crashz]

Did your mechanic rule out another head gasket failure? Maybe the block and heads have had some sealing issues?

I would check the coolant for oil and oil for coolant first. Then maybe look to see if the coolant is bubbling while running.

Any leaks around the engine? Fluid levels abnormally high or low?

[enforcer233]

Well after many months of sitting I have finally got the heads repaced. Once I had the money for the work my mechanic pulled the old heads and found multiple cracks in them. I followed Robyn's suggestion and ordered the heads from Clearwater Cylinder Heads.

Good news the ticking that I heard before is gone and the truck runs well. Notice I did not say pefect. The first thing I noticed is that under heavier acceleration I am blowing a ton of black smoke. I drove the truck west over Afton Mountain today and it downshifted several times, never did that before and the service engine soon light comes on. have been doing some reading this evening and I realize that there are a few things to check, first of all is the air intake system. Since the truck was sitting for several months there may be a mouse nest or other blockage. Second is the cat converter/soot trap. While checking the air intake I will check the turbo for free spin and excessive play. I also read about an EGR valve causing similar symptoms.

Can anyone think of anything else that needs to e checked?

Thanks

[Chevy Dooley]

Checked for any trouble codes?

[enforcer233]

I do not have a computer and I have been unable to go by an Advance Auto or Auto Zone when the service engine soon light is on.

[enforcer233]

Last night I checked the air intake system and the only thing that I found was that the tube system (EGR?) from the valve cover to the turbo had a slimy oil/water mix in it. I cleaned those parts and drove to an Advance Auto for a new air filter. While at Advance the put their scan tool on the truck and it indicated that the service engine soon light was from the "turbo superboost sensor". They also checked and do not have that part in the availible parts list, although it did show a turbo boost sensor, which they can not get.

Anyone know what is the proper terminology for this part? Is it only available from a GM service center? And where is it located?

One thing I did not mention in the previous posts is that the fuel that is in the tank has been there since last July/August when I began having problems. I had added some TEC2000 and about 20 or more ounces of Diesel Service (white bottle) to the fuel when I was trying to get what I thought was the injector to clear up. Can this old, skunky fuel be causing the black smoke condition? Or could the new injectors that I installed be putting too much fuel in?

When I drove across Afton Mountain this time the truck did not down shift and some of the smoke was gray at times instead of all black. I was not running the AC last night as I had been the previous time accorss the mountain.

Thanks

[DmaxMaverick]

The plumbing you describe is the crankcase vent. The "tuna can" on the valve cover is the CDR (crankcase depression regulator). It's job is to prevent excessive vacuum to develop during higher RPM's/load (allows contaminants to be pulled through the seals).

The sensor should be the MAP (manifold air pressure). If it, or the wiring/connectors, have failed, the PCM may see continuous "overboost" condition, and it will cause the wastegate to prevent any more than very moderate boost (if any), and may also defuel (limp mode). This can, and usually does, cause excessive black smoke and low power.

[enforcer233]

I was able to go by a local GM shop today and spoke to a mechanic who told me where to find the boost sensor. He also suggested that I check the plug to make sure it was not loose. I checked the plug and added some di-electric gel. The SES light is still on. I will see if I can pick up a new sensor tomorrow.

If this does not clear the SES light, is there any way to check the wiring with a meter to see if there is a problem there?

[enforcer233]

Just to update this thread for anyone who may have read it. I replaced the turbo boost sensor with no change, still blowing heavy black smoke, but running OK. Still did not seem to have the power that it used to have.

I went camping a few weeks ago and while crossing Afton Mountain the engine began to have a ticking sound again and even more loss of power. When i got to my destination a buddy listened to the engine and stated it sounded like an injector was fouled up again. I also noticed that the oil pressure was running around 20-30 lbs when running, but would drop to zero when idiling.

As I babied the truck home the ticking stopped for about a mile the the noise resumed as more of a thud sound, this stopped and the ticking resumed.

The enigne will occasionally throw the SES light, but it does not stay on and when idiling I hear an occasional additional tick sound that is not constant and unpredictable.

Also I the truck cut off on me one and was hard to start.

When the truck was sitting before the head replacement the batteries had gone completely out and the mechanic had a hard time getting them back up. I have replace both batteries with new ones thinking that some of the problem may be electrical. This has not helped.

I am thinking that the oil pressure senson may be bad?

The PMD may probably needs to be replaced?

One of the new heads had something happen to it again?

I am also loosing coolant somewhere on the back passenger side of the engine.

I think I covered it all.

[racer55]

First off you should not be losing coolant at all.
Check the oil for coolant contamination-is the oil level higher than it should be?
Coolant in the oil will dilute the oil and lower oil pressure as well as wipe out the bearings.
Check the wategate actuator for vacume at idle,you could have a vacume pump,boost solenoid or vacume line problem.The factory vacume lines being made of plastic can deterriorate over time.
When the engine is off the wastegate lever should move with little resistance by hand but with the engine running it should be very difficult to move.
Low boost will set your code and cause the black smoke,low power so you need to determine if you are creating boost.

When the heads were replaced were new head bolts installed?The bolts are not reusable and could be causing issues with clamping the head gaskets if the old bolts were reused.

[Robyn]

The loss of oil pressure worries me the most.
get a gauge on that thing and find out whats up there.

These engines should run at 40 PSi and drop to about 20 or so at Idle (HOT)

The ticking is also of concern.

Figure out whats up with the oil pressure first off, then move from that point on.

The SES light issue, pull tghe code and find out whats up.

Could be the vacuum pump, hoses, or the wastegate solenoid and or possibly the wastegate actuator itself.


Good luck

Missy

[enforcer233]

I had been checking the oil level when I noticed the coolant loss and it is not rising, indicating coolant in the oil. When the engine heats up is when I notice the coolant coming out and running off the exhaust downpipe. At first i thought it was the AC condenser then realized that it was too much water and when I looked under the truck at the exhaust downpipe I could see green stains on it indicating that it was dried/evaporated coolant.

I will check the wastegate and vacuum as soon as possible. I will see if I can find someone who can get a guage on the oil pressure to see if it is still good or if it is the sensor.

I do not know if the mechanic who replaced the heads for me used new bolts or not. I will ask.

I would have to drive the truck about 20 miles to get to someone that has a scan tool to check the SES light codes. That scares me a bit to drive it that far with the problems I have been having. I can tow it somewhere to have those checked.

[rameye]

I think you need to get your priorities in order here..

If you have a an internal coolant leak (head gasket or worse) why would you worry about codes and sensors???

If you have coolant in your oil...refrain from driving your vehicle! The coolant likes to eat your engine bearings...it especially likes turbo bearings!!

Anyway...first things first..fix/solve/diagnose your coolant leak....then go after codes and sensors and running rough.

Bring it back to Mr Goodwrench who did the gaskets and let him have at it.

my $.02

[racer55]

I had been checking the oil level when I noticed the coolant loss and it is not rising, indicating coolant in the oil. When the engine heats up is when I notice the coolant coming out and running off the exhaust downpipe. At first i thought it was the AC condenser then realized that it was too much water and when I looked under the truck at the exhaust downpipe I could see green stains on it indicating that it was dried/evaporated coolant.

I will check the wastegate and vacuum as soon as possible. I will see if I can find someone who can get a guage on the oil pressure to see if it is still good or if it is the sensor.

I do not know if the mechanic who replaced the heads for me used new bolts or not. I will ask.

I would have to drive the truck about 20 miles to get to someone that has a scan tool to check the SES light codes. That scares me a bit to drive it that far with the problems I have been having. I can tow it somewhere to have those checked.
You should have the cooling system pressure tested.
Also the area of your coolant loss could be something as simple as an overfull resivoir or leaking resivoir?You might just have a bad rad cap.Get the cooling system tested to pinpoint the leak.