6.5L
Old Iron Runner
Gm Guy, I didn't really peg you for a manual enthusiast after going through your signature haha I love mine
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6.5 newbie with what appears to be a blown turbo- what say you?
- Thread starter Sentinelist
- Start date
Sentinelist
Active Member
Well I haven't had time to go through the checklist yet (especially as I found my 7-way plug for the camper drained both batteries, so out that went), but here's what I did find in the hour I had today.
The inlet side of the turbo has zero play and spins just fine with little resistance- feels normal, not broken. Good sign I hope. I cannot budge the waste gate one way or the other- should I be able to? The air box hose connection seemed to have a good bit of oil residue on it, as did the small hose connection on top of it above the turbo (sorry, still new here), and even the turbo inlet side before the fan blades. I wiped it all out, pitch black. The air filter was pretty dirty as well, so I replaced that with a new STP that I found under the backseat in the truck. I'll drop in a K&N later, if those are OK for these mills. The fuel filter/FFM seemed OK, though the bottom 3/4 of the element was very dark, maybe black. Though I couldn't remove the 'last resort' filter easily in the time I had, but it was in there, canister full of fuel, smelled normal, no rotten eggs. There were some light wisps of smoke coming out of the canister, though I did have the key in to ACC at this time. I noticed some oil residue coming out from around the lower-central bolt on the air intake manifold.
So, turbo OK we think? What next? I haven't gotten down to the lift pump, but I messaged the PO today and he said it was replaced in the last few years, as were the injectors, but he only thinks the IP was rebuilt possibly by the guy before him, which would have been at least 7 years ago.
The inlet side of the turbo has zero play and spins just fine with little resistance- feels normal, not broken. Good sign I hope. I cannot budge the waste gate one way or the other- should I be able to? The air box hose connection seemed to have a good bit of oil residue on it, as did the small hose connection on top of it above the turbo (sorry, still new here), and even the turbo inlet side before the fan blades. I wiped it all out, pitch black. The air filter was pretty dirty as well, so I replaced that with a new STP that I found under the backseat in the truck. I'll drop in a K&N later, if those are OK for these mills. The fuel filter/FFM seemed OK, though the bottom 3/4 of the element was very dark, maybe black. Though I couldn't remove the 'last resort' filter easily in the time I had, but it was in there, canister full of fuel, smelled normal, no rotten eggs. There were some light wisps of smoke coming out of the canister, though I did have the key in to ACC at this time. I noticed some oil residue coming out from around the lower-central bolt on the air intake manifold.
So, turbo OK we think? What next? I haven't gotten down to the lift pump, but I messaged the PO today and he said it was replaced in the last few years, as were the injectors, but he only thinks the IP was rebuilt possibly by the guy before him, which would have been at least 7 years ago.
Will L.
Well-Known Member
Sounds like wastegate is locked up -
Do not waste $ on a k&n. do the research and you'll find out its a bad choice, and I have bought 3. A. Delco flows better, takes longer to plug up, and k&n let's more fine dirt particles threw causing quicker bearing wear. There are long life filters available, just don't go k&n.
Do not waste $ on a k&n. do the research and you'll find out its a bad choice, and I have bought 3. A. Delco flows better, takes longer to plug up, and k&n let's more fine dirt particles threw causing quicker bearing wear. There are long life filters available, just don't go k&n.
Paveltolz
Доверяй, но проверяй
Confirm what Will said about the K&N. After running one for a couple of years I had noticeable wear on the leading edges of my blades. A friend was looking at my turbo and said, "I see you've been running a K&N." That hurt!
On the vacuum controlled units (I know yours isn't), they should move freely with the motor off but not when running. Not sure how the 93 waste gates work as apposed to the vacuum units but I'd think it would be similar. I'll defer to Will and others for the definitive answers.
On the vacuum controlled units (I know yours isn't), they should move freely with the motor off but not when running. Not sure how the 93 waste gates work as apposed to the vacuum units but I'd think it would be similar. I'll defer to Will and others for the definitive answers.
IIRC the 93 has a pretty stiff spring. You may need to disconnect it from WG. The WG should then move freely.
Air filter: I like the AEM dry element for the K47 box. Thats another highly recomended mod for you to do. The 98 and newer had a higher flowing air filter with more surface area on the filter, its called a K47 option.
Yes I can get the AEM element.
Sounds like you need a fuel filter to if it was black.
Air filter: I like the AEM dry element for the K47 box. Thats another highly recomended mod for you to do. The 98 and newer had a higher flowing air filter with more surface area on the filter, its called a K47 option.
Yes I can get the AEM element.
Sounds like you need a fuel filter to if it was black.
3500GMC
What T F, over
The wastegate rod moves toward the rear of the truck to OPEN. I can move mine by hand.
Sentinelist
Active Member
Ok thanks, guys. I'll take another look at the wastegate and see if I can disconnect to move it. It does appear to be in the rear/open position with the truck off. I'll try and get the truck started today as well and see if that changes to front/closed. I'll find a new fuel filter as well (checking your site first, Leroy!).
I'll stay away from the K&Ns, having heard similar things elsewhere too. I run them in my other cars as well but have been thinking about going back to the dry elements lately. The 'recharging' process can be a PITA just from a time standpoint.
I'll stay away from the K&Ns, having heard similar things elsewhere too. I run them in my other cars as well but have been thinking about going back to the dry elements lately. The 'recharging' process can be a PITA just from a time standpoint.
I have new Stanadyne filters in stock (metal top) $19. but not on the site. Email me if you'd like one with a list of items you want and I'll fire you back an invoice.
GM Guy
Manual Trans. 2WD Enthusiast
97+ 6.5L trucks came with the round element air cleaner. AKA the K47 air cleaner. I highly recommend it, I buy as many as I can.
Sentinelist
Active Member
Ok, so would buying a new wastegate be an ideal next step? Would not relieving the back pressure (?) cause the symptoms I initially described/could the wastegate be the culprit? I can't seem to find any for my 1993, most are advertised for 1994+. None for the GM-3. Any recommendations?
The FFM (will still replace) and air filters may be side thoughts at this point, but still definitely open to new ideas on how to resolve this!
The FFM (will still replace) and air filters may be side thoughts at this point, but still definitely open to new ideas on how to resolve this!
6.5L
Old Iron Runner
Even if the wastegate was locked up, I can't really see it causing the issues you are having. I couldn't push my wastegate back on mine without disconnecting it. There is a little e-clip you can take off right at the wastegate on the turbine housing and then you should be able to move the wastegate front to back. With being towards the front as closed. I would still check your lift pump and possibly tank sock. Be sure to bypass the OPS for your lift pump. I have had good luck with my AFE as far as filters go. And you could maybe have a seal out on the turbine side of the turbo that is leaking oil if you can't find a leak anywhere. Won't always be represented with shaft play. My hx35 had it's turbine seal out when I got it but didn't show shaft play. Just an idea. And there will usually always be oil in the intake from right before your turbo all the way through the intake. Caused indirectly by the CDR valve on the passenger side valve cover. That could have possibly gone bad as well. Could be a easily replaceable item.
Big T
Well-Known Member
I have two (2) used GM 5 turbos complete, plus a good working vac pump. I'll let them go cheap, if that's the direction you want to go. Send me a PM.
Sentinelist
Active Member
Ok- how can I bypass the OPS (oil pressure switch?)? Should I for good? Please tell me more about this CDR valve. I can't find much about it. Thanks!
P.s. I'm ordering parts no later than tomorrow so I can get them expedited to my door for some Friday installs. I still haven't ruled out the turbo. Time is tight, having a shop do it, hoping to get this thing back on the road Saturday afternoon for a short trip.
GM Guy
Manual Trans. 2WD Enthusiast
Kennedy diesel sells the OPS relay kit if you arent into wiring.
basically the factory wiring relies on the OPS to carry the load for the LP. the contacts wear out, and after a while your LP quits working, even though it still may be in good shape. a new OPS gets everything going again.
it is a problem, but honestly I just put a new AC delco OPS in and dont have issues for a few years. Just a plain new AC Delco OPS will be a quick way to get it going again.
basically the factory wiring relies on the OPS to carry the load for the LP. the contacts wear out, and after a while your LP quits working, even though it still may be in good shape. a new OPS gets everything going again.
it is a problem, but honestly I just put a new AC delco OPS in and dont have issues for a few years. Just a plain new AC Delco OPS will be a quick way to get it going again.
Clear your mind of parts you want to replace and start over.
NO! it's not that - START OVER!
You have a weird sound, loss of power, and engine stalling. Throwing parts at isn't going to fix it and will waste money. Sometimes we get bad parts and start over the troubleshooting then. parts replaced 30 seconds or years ago do not give them a free pass.
By the book first you want to make sure you don't have air in the lines. You verify this by using a clear return line off the IP. Air would normally clear out, but, constant air is an issue and this is what the clear line tests for. Air leaks from a bad hose, rusted pickup assembly, etc. Air includes diesel vapor. A restriction in the fuel line will have the IP boil diesel in the fuel line. Kinked hoses, plugged tank socks, water in fuel are all restrictions.
A pressure test from the water drain port is in order. The Oil Pressure Switch that runs the lift pump goes bad often. The lift pumps IMO are the biggest turd supplied with these trucks 2nd only to the restrictive GM3 turbo. "0" is a useless reading as you need a gauge that reads a vacuum as well as pressure. You can snap the throttle open and hold the engine on the 3600 RPM governor and have 0-5 PSI. A vacuum is a bad sign. You need to hit max RPM as the IP bypasses a lot of fuel and even more fuel at high RPM. Idle readings are cute - but the real problems can show up at higher RPM. These engines don't start or run well without a working lift pump.
Assuming you don't have water in fuel or any fuel restrictions - aka getting 5+ psi at idle at the water drain we move on.
Check codes for transmission issues. No SES light comes on for any faults the 1993 ECM, 'transmission' computer, finds.
Look at the passenger side of the IP, injection pump. You see a lever on it from the throttle to a pin at the bottom of the pump. This is a timing retard lever for higher loads. With the engine at idle push this lever in at the bottom with a large screwdriver. The engine should start to run bad and nearly stall with possible white smoke. This somewhat verifies the timing piston in the IP is working - a common failure in these old DB2 pumps is for the advance piston to lock up. No change with the pin in is bad news - rebuild IP time.
Next is the dreaded difficult 'hot start' issue from a worn head and rotor in the IP. Again the above lift pump not working will aggravate the difficult starting with a hot engine. When the engine is hot it may be difficult to start like when your camper was installed. No glow plugs are used because the controller is hot and won't kick them in. Thin fuel from being hot and a worn head/rotor makes starting difficult: Long cranking or no start. Cold water dumped on the injector line side of the IP causing instant starting verifies this condition.
We have even more fun for 'stalling'. The idle speed needs to be set every 6 months. A light sensor digital tach with reflective tape is one way to set this. You adjust the screw in the IP when hot at idle to get 650 RPM. Then you kick the cold advance on and blip the throttle. Then you set the cold advance to 750 RPM. Hopefully the TPS doesn't need adjustment after that.
You do need to verify the cold start switch on the coolant crossover is working. As the engine warms up you will hear the rattle get less and RPM drop when it kicks off. You have to step on the throttle with the key on and engine off before starting cold to set the cold advance high idle - allow the idle plunger to drop anyway.
Next you can have a shop verify timing as the timing chain stretches over time and retards the IP timing.
From your description I suggest fuel delivery problems as described above. Oil use doesn't tell you anything. Worked hard like freeway speed with a sail like camper these engines can burn 1 quart (~1 liter) in 500 miles. White smoke after start-up is a cold engine and likely will smell like fuel. Lots of white smoke is likely a timing issue.
Last a bigger turbo gives you power over 2200 RPM. The factory turbo becomes an asthma attack over 2200 RPM.
NO! it's not that - START OVER!
You have a weird sound, loss of power, and engine stalling. Throwing parts at isn't going to fix it and will waste money. Sometimes we get bad parts and start over the troubleshooting then. parts replaced 30 seconds or years ago do not give them a free pass.
By the book first you want to make sure you don't have air in the lines. You verify this by using a clear return line off the IP. Air would normally clear out, but, constant air is an issue and this is what the clear line tests for. Air leaks from a bad hose, rusted pickup assembly, etc. Air includes diesel vapor. A restriction in the fuel line will have the IP boil diesel in the fuel line. Kinked hoses, plugged tank socks, water in fuel are all restrictions.
A pressure test from the water drain port is in order. The Oil Pressure Switch that runs the lift pump goes bad often. The lift pumps IMO are the biggest turd supplied with these trucks 2nd only to the restrictive GM3 turbo. "0" is a useless reading as you need a gauge that reads a vacuum as well as pressure. You can snap the throttle open and hold the engine on the 3600 RPM governor and have 0-5 PSI. A vacuum is a bad sign. You need to hit max RPM as the IP bypasses a lot of fuel and even more fuel at high RPM. Idle readings are cute - but the real problems can show up at higher RPM. These engines don't start or run well without a working lift pump.
Assuming you don't have water in fuel or any fuel restrictions - aka getting 5+ psi at idle at the water drain we move on.
Check codes for transmission issues. No SES light comes on for any faults the 1993 ECM, 'transmission' computer, finds.
Look at the passenger side of the IP, injection pump. You see a lever on it from the throttle to a pin at the bottom of the pump. This is a timing retard lever for higher loads. With the engine at idle push this lever in at the bottom with a large screwdriver. The engine should start to run bad and nearly stall with possible white smoke. This somewhat verifies the timing piston in the IP is working - a common failure in these old DB2 pumps is for the advance piston to lock up. No change with the pin in is bad news - rebuild IP time.
Next is the dreaded difficult 'hot start' issue from a worn head and rotor in the IP. Again the above lift pump not working will aggravate the difficult starting with a hot engine. When the engine is hot it may be difficult to start like when your camper was installed. No glow plugs are used because the controller is hot and won't kick them in. Thin fuel from being hot and a worn head/rotor makes starting difficult: Long cranking or no start. Cold water dumped on the injector line side of the IP causing instant starting verifies this condition.
We have even more fun for 'stalling'. The idle speed needs to be set every 6 months. A light sensor digital tach with reflective tape is one way to set this. You adjust the screw in the IP when hot at idle to get 650 RPM. Then you kick the cold advance on and blip the throttle. Then you set the cold advance to 750 RPM. Hopefully the TPS doesn't need adjustment after that.
You do need to verify the cold start switch on the coolant crossover is working. As the engine warms up you will hear the rattle get less and RPM drop when it kicks off. You have to step on the throttle with the key on and engine off before starting cold to set the cold advance high idle - allow the idle plunger to drop anyway.
Next you can have a shop verify timing as the timing chain stretches over time and retards the IP timing.
From your description I suggest fuel delivery problems as described above. Oil use doesn't tell you anything. Worked hard like freeway speed with a sail like camper these engines can burn 1 quart (~1 liter) in 500 miles. White smoke after start-up is a cold engine and likely will smell like fuel. Lots of white smoke is likely a timing issue.
Last a bigger turbo gives you power over 2200 RPM. The factory turbo becomes an asthma attack over 2200 RPM.
Sentinelist
Active Member
Thank you both- great info to keep digging with. Added to the list! Let me pair that with the order I just placed with Leroy this afternoon and you can tell me how best to proceed. 
- ATT
- Diamond Eye
- Stanadyne FFM filter, screen, and gauge port
- Walbro LP and bypass kit
- Pre-LP filter kit
Plans: truck is going in (again, for the sake of time for me this month) to the shop first thing Friday morning. They will install the new LP, pre-LP filter kit, drop the fuel tank, check for bugs, throw away the sock, and test fuel up to the LP. I will fill in the other suggestions in the middle of all that where I can. Afterwards (I guess regardless now), I'll be installing the new ATT and finding an exhaust shop to get the Diamond Eye on there ASAP. I justified all this to the wife over dinner tonight as making sure I was getting rid of all the weaknesses so it wouldn't strand us in the wilderness.
- ATT
- Diamond Eye
- Stanadyne FFM filter, screen, and gauge port
- Walbro LP and bypass kit
- Pre-LP filter kit
Plans: truck is going in (again, for the sake of time for me this month) to the shop first thing Friday morning. They will install the new LP, pre-LP filter kit, drop the fuel tank, check for bugs, throw away the sock, and test fuel up to the LP. I will fill in the other suggestions in the middle of all that where I can. Afterwards (I guess regardless now), I'll be installing the new ATT and finding an exhaust shop to get the Diamond Eye on there ASAP. I justified all this to the wife over dinner tonight as making sure I was getting rid of all the weaknesses so it wouldn't strand us in the wilderness.
Thank you again for the order. DE is drop shipping right from Dallas so you "might" have tomorrow. Everything else went today, but may not load on USPS truck til tomorrow.
Will L.
Well-Known Member
Jd, welcome to the forum.
You should start a new thread (with a picture would help) so more people can see it, and it doesn't confuse the guy who is asking questions on his truck for this thread. That said -you have the two main mounting bolts
Then the very important rear bracket. It sounds like the rear bracket is not on correctly, that's why a picture would help verify.
Sentinelist keep in mind this response is not regarding your truck.
You should start a new thread (with a picture would help) so more people can see it, and it doesn't confuse the guy who is asking questions on his truck for this thread. That said -you have the two main mounting bolts
Then the very important rear bracket. It sounds like the rear bracket is not on correctly, that's why a picture would help verify.
Sentinelist keep in mind this response is not regarding your truck.
Sentinelist
Active Member
Thanks, Will.
Update, though perhaps not too surprising. After tending the battery for a day the truck started cold but stalled 10-20 seconds later. A few repeated attempts resulted in the same, though I'm definitely getting fuel out of the overflow tube up top still. However, now I'm concerned I won't be able to get the truck to my shop for Friday morning. Trip all but cancelled, will likely be wrenching now instead.
Any threads on how to drop the fuel tank without removing the bed? I'm currently at a loss on this part.
The exhaust arrived today, Leroy!
Update, though perhaps not too surprising. After tending the battery for a day the truck started cold but stalled 10-20 seconds later. A few repeated attempts resulted in the same, though I'm definitely getting fuel out of the overflow tube up top still. However, now I'm concerned I won't be able to get the truck to my shop for Friday morning. Trip all but cancelled, will likely be wrenching now instead.
Any threads on how to drop the fuel tank without removing the bed? I'm currently at a loss on this part.
The exhaust arrived today, Leroy!