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6.5L Newbie

Remcd44

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Hello, I have recently purchased a 1995 Chevy Silverado 2500 with 208K showing. I was told by the person I bought it from that it just had a couple of oil leaks. I took it for a test drive and discovered the transmission was in need of repair. The transfer case was questionable and the engine had more oil leaks than I could count. I made the decision to buy the truck based upon the general condition as a shell that had not been abused. The only thing that appeared "molested" was the engine. Upon further investigation being unfamiliar with the 6.5L I discovered blow by coming out of the dipstick tube and crankcase breather. The previous owner added a cold air intake but did not attach the OEM crankcase breather to the intake side of the turbo. Needless to say there is quite a bit of blow by coming out there to. Here is my question; 1. How much blow by is acceptable and 2. I am thinking about purchasing a drop in optimizer engine from Bostic Motors. Does anyone have any knowledge of them good or bad? Thanks
 

Will L.

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Oh yeah, take as much time as possible and read all the stickies. I would say a 6.5 newbie could learn as much just reading 10 hours here as takes a mechanic in a shop learns in a year about these engines.

It will save you so much money, time, and aggravation...
 

WarWagon

Well it hits on 7 of 8...
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Welcome!

What is your intended use and goals for this truck? We are more than happy to help you spend your money or be frugal with it. As above blowby isn't the end of the world, but, it going to leak oil with lots of it. Oil is cheap if you just need a runner. The CDR to the intake can help with this to a point. #1 reason for blowby on IDI diesels, like the 6.2/6.5, is the engine getting over 210 Engine coolant temp and the rings loose tension. Doesn't need to be in the red, but, it may have been pretty hot relieve to IDI temp limits. Of course, worn out goes for any engine.

Some people do buy a nice shell and freshen up the powertrain. Or build it for what they want it to do. Some run it as is till they have to do something to keep it moving under it's own power.
 

Jaryd

Extremely Deplorable
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Oh yeah, take as much time as possible and read all the stickies. I would say a 6.5 newbie could learn as much just reading 10 hours here as takes a mechanic in a shop learns in a year about these engines.

It will save you so much money, time, and aggravation...
Amen to that. This place has very good info on these engines and trucks
 

JayTheCPA

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Welcome to TTS!

For the intake, if it is not a closed box design, ditch it and go for a closed box. Preference is one that uses the cylindrical style filter. Alternatively, the S&B system uses a round pyramid filter design which has a good reputation. Reason for the comment about a closed air box is that some aftermarket manufacturer's make an open box system for the 6.5 and call it cold air intake, but in reality it sucks in warm air from the engine bay. Another reason to make sure the box is a closed design is that the open box makes a noticeable amount of drone. Also IIRC, the '95 might have a snorkel in the fender above the wheel well where the OE box should have connected. If the snorkel is present, remove it.

While tearing into the motor, look to make sure the starter still has its support bracket. If it does not, it is an inexpensive part that will prevent destruction of the block. This bracket prevents risk that the starter will crack the block at the mount hole. If this happens, there is no repair and the only way forward is a replacement block.

If some of the leaks are coming from the valve covers, you will need new ones as they are held in place by sealant and the sealant does not want to easily let go of the covers. The bolts are pretty much there to squish the sealant as it cures.

Last note. The injection system needs lubrication additive to the current ULSD. Given the comments about neglect, chances are good the previous owner just added fuel, so consider adding some cleaner solution and lube to the next full tank of fuel and run that tank a little hard. After that, make sure to add lube to the fuel.
 

Remcd44

New Member
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run from bostic motors. Blowby is a hard thing to determine. Mostly a matter of how much you can live with. My 96 ran great but had tons of blowby by the time it died with 306k on the clock
Thanks for the reply. Hearing your story makes me more comfortable with driving mine the way it is.
 

Remcd44

New Member
Messages
10
Reaction score
11
Location
97525
Welcome!

What is your intended use and goals for this truck? We are more than happy to help you spend your money or be frugal with it. As above blowby isn't the end of the world, but, it going to leak oil with lots of it. Oil is cheap if you just need a runner. The CDR to the intake can help with this to a point. #1 reason for blowby on IDI diesels, like the 6.2/6.5, is the engine getting over 210 Engine coolant temp and the rings loose tension. Doesn't need to be in the red, but, it may have been pretty hot relieve to IDI temp limits. Of course, worn out goes for any engine.

Some people do buy a nice shell and freshen up the powertrain. Or build it for what they want it to do. Some run it as is till they have to do something to keep it moving under it's own power.
Mostly it will just be a daily grocery getter and the occasional trailering of my 7000lb tractor. The oil consumption is surprisingly minimal and really just more of an embarrassment. I don't like leaving little oil drops every place I park. This is the first vehicle I have ever owned that has so many minuscule leaks I park with a cardboard "diaper" underneath! One of the leaks was the radiator which I have replaced and the other was the trans which is now rebuilt as well. The leaks are really hard to pinpoint but one of my suspicions are the oil cooler lines since I see many places selling them as an upgrade. I also suspect the fuel filter housing because occasionally I smell raw diesel around the truck but have no diesel spots on the ground. The starter needed replacing as well and the bracket that everyone warns of having to be on there was missing. For the life of me I cant figure out why the previous owner broke a chunk out of the front lower cover of the trans to replace the starter. Thank God for this forum that I found it missing based upon everyone's shared knowledge! I have put the stock air cleaner back on and the CDR valve which had been removed by the previous owner and it really has slowed the leaks down. I purchased a 94 GMC Sierra that is bone stock for parts. Is there any way to tell if the engine has been over temped? Something else I noticed was oil pooling on top of the flats on the intake ports and upon further inspection found hairline cracks in it. Has anyone else experienced this? It's going to take some time to return this neglected truck back to it's original factory condition and by the time I'm finished I will have about 15K into it. That beats the hell out of 70K for a new Duramax! One last thing, what is an "IDI" diesel?
 

Remcd44

New Member
Messages
10
Reaction score
11
Location
97525
Oh yeah, take as much time as possible and read all the stickies. I would say a 6.5 newbie could learn as much just reading 10 hours here as takes a mechanic in a shop learns in a year about these engines.

It will save you so much money, time, and aggravation...
Right on Will L. At this point in my life not having the aggravation is worth more to me than anything else!
 

Remcd44

New Member
Messages
10
Reaction score
11
Location
97525
Welcome to TTS!

For the intake, if it is not a closed box design, ditch it and go for a closed box. Preference is one that uses the cylindrical style filter. Alternatively, the S&B system uses a round pyramid filter design which has a good reputation. Reason for the comment about a closed air box is that some aftermarket manufacturer's make an open box system for the 6.5 and call it cold air intake, but in reality it sucks in warm air from the engine bay. Another reason to make sure the box is a closed design is that the open box makes a noticeable amount of drone. Also IIRC, the '95 might have a snorkel in the fender above the wheel well where the OE box should have connected. If the snorkel is present, remove it.

While tearing into the motor, look to make sure the starter still has its support bracket. If it does not, it is an inexpensive part that will prevent destruction of the block. This bracket prevents risk that the starter will crack the block at the mount hole. If this happens, there is no repair and the only way forward is a replacement block.

If some of the leaks are coming from the valve covers, you will need new ones as they are held in place by sealant and the sealant does not want to easily let go of the covers. The bolts are pretty much there to squish the sealant as it cures.

Last note. The injection system needs lubrication additive to the current ULSD. Given the comments about neglect, chances are good the previous owner just added fuel, so consider adding some cleaner solution and lube to the next full tank of fuel and run that tank a little hard. After that, make sure to add lube to the fuel.
Thank you for the remark about the starter. I feel like I dodged a bullet by finding the bracket missing!
 
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