How much damage have I caused?
#21
09-09-2018, 09:41 PM
Today i had some spare time to actually do some work on the truck. I rented the head gasket blue liquid kit from auto zone. I repeated the test several times and every time the fluid turned yellow for a bad head gasket. Ok not so bad i was expecting that due to rough idle.
I also used their OEM brand compression tester kit. I was not pleased to see the numbers.
starting in the front of the engine on the pass side the numbers were as follows.
85psi, 60psi,140psi
starting in the front of the engine on the drivers side numbers were as follows:
100psi, 70psi, 155,psi
the numbers seem very irregular and i didnt read such good reviews about this brand of compression kits. Anyways this is the first time ive ever done a compression test on any vehicle.
Based on these numbers is it safe to say this engine is not worth throwing new heads into?
I also used their OEM brand compression tester kit. I was not pleased to see the numbers.
starting in the front of the engine on the pass side the numbers were as follows.
85psi, 60psi,140psi
starting in the front of the engine on the drivers side numbers were as follows:
100psi, 70psi, 155,psi
the numbers seem very irregular and i didnt read such good reviews about this brand of compression kits. Anyways this is the first time ive ever done a compression test on any vehicle.
Based on these numbers is it safe to say this engine is not worth throwing new heads into?
#23
09-09-2018, 10:17 PM
#24
09-09-2018, 11:23 PM
Champion
Heh. Cross fingers and pray, or do a full tear down.
I'd visually examine all the upper rings, and if you're pulling the oil pan, the bottom rings; see if there's any obviously broken ones etc.
Also, check the cylinder walls to see if the factory crosshatching is still there and if there's a ridge at the top of the cylinder (the crosshatching can wear off and the ridge indicates cylinder wall wear). I doubt you'll see EITHER, but not a bad idea to check for them.
If you see the cross hatching, that's really good. If you see a big ridge, that's really bad.
RwP
I'd visually examine all the upper rings, and if you're pulling the oil pan, the bottom rings; see if there's any obviously broken ones etc.
Also, check the cylinder walls to see if the factory crosshatching is still there and if there's a ridge at the top of the cylinder (the crosshatching can wear off and the ridge indicates cylinder wall wear). I doubt you'll see EITHER, but not a bad idea to check for them.
If you see the cross hatching, that's really good. If you see a big ridge, that's really bad.
RwP
#25
09-10-2018, 07:17 AM
Not much way to do that other then what Ralph suggested above..... How many miles are on the motor? Before overheating, was oil pressure good? Did it use any oil between changes?
You are kinda all over the place with what you are going to do, (and I would be the same way!!)
IMO you need to stop and consider the following
1. What is the overall condition of the truck? is it worth repairing?
2. What are your mechanical capabilities, and do you have a place to do all of this work?
3. What is your time worth?
4. how important is the cost?
If you have the spare time, you could get a gasket set, and head bolts from rock auto for less then $80.00 + shipping, clean up what you can, put the motor back together, get a new radiator, t-stat for $125.00 and hope for the best.
But, keep in mind, all that corrosion you see in the radiator is in the block..... The freeze plugs are likely very thin.....
Also, the tapping you heard, (from overheating and pegged the gauge) could have caused other damage to the motor. So again, no guarantee's its going to be ok, even if it was running fine before overheating.
Your other option would be to bite the bullet and buy a remanufactured long block.
Rock auto has this for $1361.xx exchange + shipping. https://www.rockauto.com/en/moreinfo...sn=472&jsn=472
But the advantages are
1. 3 year warranty
2. guaranteed to be correct
3. Everything inside the engine has been either inspected, replaced, machined,etc
At the end of the day, you are looking at $80.00 + shipping (minimum) to try and repair, or $1361.00 + $158.00 shipping for a long block. (in my area anyways)
Then of course all the little misc. things, ie radiator, antifreeze, oil, filter, etc. ($200.00?) that you are going to have either way you go.
#26
09-10-2018, 07:55 AM
Could also toss a used motor at it......
If you have an air compressor, could try doing a cylinder leakdown test. That would tell you where your compression was going. (out the valves, around the rings, or out the radiator......) Heads on these era trucks were notorious for cracking, and since you overheated pretty bad, it almost guaranteed that yours are going to be. (which means, replacements.....) That would be about half the cost of the new long block... If the truck is in good shape, does what you need it to, and you LIKE it, Long Block.
If you have an air compressor, could try doing a cylinder leakdown test. That would tell you where your compression was going. (out the valves, around the rings, or out the radiator......) Heads on these era trucks were notorious for cracking, and since you overheated pretty bad, it almost guaranteed that yours are going to be. (which means, replacements.....) That would be about half the cost of the new long block... If the truck is in good shape, does what you need it to, and you LIKE it, Long Block.
#27
09-10-2018, 09:22 AM
Not much way to do that other then what Ralph suggested above..... How many miles are on the motor? Before overheating, was oil pressure good? Did it use any oil between changes?
-170k, oil pressure was perfect and truck used no oil
You are kinda all over the place with what you are going to do, (and I would be the same way!!)
IMO you need to stop and consider the following
1. What is the overall condition of the truck? is it worth repairing?
-Absolutely. Interior/exterior are mint. Probably cleanest body dakota of this year in my state.
2. What are your mechanical capabilities, and do you have a place to do all of this work?
-I have a garage and tools to do a head swap, not a motor replacement, id need some help amd a cherry picker.
3. What is your time worth?
-This is the part that worries me
4. how important is the cost?
- I love the truck i spent months bringiny it back cosmetically.
If you have the spare time, you could get a gasket set, and head bolts from rock auto for less then $80.00 + shipping, clean up what you can, put the motor back together, get a new radiator, t-stat for $125.00 and hope for the best.
But, keep in mind, all that corrosion you see in the radiator is in the block..... The freeze plugs are likely very thin.....
Also, the tapping you heard, (from overheating and pegged the gauge) could have caused other damage to the motor. So again, no guarantee's its going to be ok, even if it was running fine before overheating.
Your other option would be to bite the bullet and buy a remanufactured long block.
Rock auto has this for $1361.xx exchange + shipping. https://www.rockauto.com/en/moreinfo...sn=472&jsn=472
But the advantages are
1. 3 year warranty
2. guaranteed to be correct
3. Everything inside the engine has been either inspected, replaced, machined,etc
At the end of the day, you are looking at $80.00 + shipping (minimum) to try and repair, or $1361.00 + $158.00 shipping for a long block. (in my area anyways)
- I would at minimum throw heads at it. It currently runs with no funny noises but it has a rough idle and very visible white cloud out the exhaust from the head gasket.
Then of course all the little misc. things, ie radiator, antifreeze, oil, filter, etc. ($200.00?) that you are going to have either way you go.
Im going to tear into it and see what i can see. I dont need the vehicle for work i have 4 other cars. This way i can take my time but winter is around the corner in Michigan.
Last edited by BlueLiner; 09-10-2018 at 09:34 AM.
#28
09-28-2018, 11:20 PM
#29
09-30-2018, 09:22 AM
I see that someone mentioned a timing chain. the 3.9s were harder on them than the V8s because of the 6 cyl engines "odd fire" design. Seriously its like 5 more fasteners and you have the timing cover off. Little as compared to having to do a t chain from scratch..
think about this... if that t chain does go, you will ruin your new valves when they kiss the pistons and bend. so back to square one.
T chains are not that expensive. I would certainly not go with the cheapest option. I too like double rollers, if you go with a decent quality set you really wont need the tensioner. but they started putting them on the 3.9s and not on the V8s even though the same chain and gears fit both (tensioner would work on the V8 too) because of the 6 cyl tendency to beat the chain up more.
think about this... if that t chain does go, you will ruin your new valves when they kiss the pistons and bend. so back to square one.
T chains are not that expensive. I would certainly not go with the cheapest option. I too like double rollers, if you go with a decent quality set you really wont need the tensioner. but they started putting them on the 3.9s and not on the V8s even though the same chain and gears fit both (tensioner would work on the V8 too) because of the 6 cyl tendency to beat the chain up more.
#30
09-30-2018, 12:15 PM
I see that someone mentioned a timing chain. the 3.9s were harder on them than the V8s because of the 6 cyl engines "odd fire" design. Seriously its like 5 more fasteners and you have the timing cover off. Little as compared to having to do a t chain from scratch..
think about this... if that t chain does go, you will ruin your new valves when they kiss the pistons and bend. so back to square one.
T chains are not that expensive. I would certainly not go with the cheapest option. I too like double rollers, if you go with a decent quality set you really wont need the tensioner. but they started putting them on the 3.9s and not on the V8s even though the same chain and gears fit both (tensioner would work on the V8 too) because of the 6 cyl tendency to beat the chain up more.
think about this... if that t chain does go, you will ruin your new valves when they kiss the pistons and bend. so back to square one.
T chains are not that expensive. I would certainly not go with the cheapest option. I too like double rollers, if you go with a decent quality set you really wont need the tensioner. but they started putting them on the 3.9s and not on the V8s even though the same chain and gears fit both (tensioner would work on the V8 too) because of the 6 cyl tendency to beat the chain up more.
