Hi all,

I got a 91 Dakota for free as my beater truck! Took me a month to fix the electrical nonsense but now electrical is all good! I am blowing coolant in the exhaust and she will overheat once she warms up. This is how I got her. Fed her coolant to get her home...

Guessing at the minimum the thermostat is stuck closed which is what probably caused the whole mess to begin with. I topped off the reservoir yet the radiator stayed empty. So as part of my overhaul here I got new hoses, thermostat, water pump.

SHOULD I put in a new radiator right away? The old one doesn't look great, scaly, a little corroded looking... But it's $$$ and maybe mine is okay???

Hoping the exhaust smoke is just a head gasket. Definitely coolant in the exhaust. Can smell it when I wipe my finger in the tailpipe. In order to diagnose cracked head or warped head versus head gasket I will need to tear it down regardless...

I've never torn an engine down before. I have the factory service manual here and the Haynes book, they both give good information. But there's a lot of stuff to come out of the way from what it looks like.

So I'm looking to see if anyone here has some pointers for me or even a more detailed guide?? Wish me luck!! At the same time I'm putting in a new alternator and water pump, serpentine belt (duh). Might as well get plug wires, cap / rotor... while it will be torn down. New plugs? Looking for advice!!

I've worked on cars but not done a lot as far as timing, etc. Never tore down an engine. Are the stock head aluminum?

Thanks!

Damian

 

If you ever lift one, you'd know the stock heads are cast iron.

1991? Might want to check that VIN - the first 1992s were built late 1991.

Is it fuel injected (rails with an injectgor per cylinder) or throttle body injected (two injectors in the throttle body)?

Get you a good set of torque wrenches; buy new head bolts; I'd replace that radiator - or get the current one rebuilt if it's all metal! - and if it's a Magnum (SEFI/MPFI), I'd consider new heads.

If you can find some EngineQuest CH318 heads, I'd just plan on them. The current heads may be cracked; it's common on Magnum heads.

Edlebrock heads can be had at Summit for right at $1,000 each (!!!!). Jegs has some house brand heads for $480 each assembled, so ready to drop in, if you trust their building. (They have other heads also; the Mopar Performance ones are about $1,500 each.)

I would bite the bullet and pick up the ARP fastener set for the engine; you need to replace the factory head bolts ANYWAY. The 2019 catalog shows 544-9?01 (where ? = 5,6,7, or 8 depending on 6 or 12 point and black or stainless) for the entire engine set; although that's for LA blocks, should be close for the Magnum. Be sure to use their thread lube and sealer if you use them! (If not, at least get new ones, even if they're Grade 8 or 10.9 bolts from Lowe's or Home Depot ... )

Plugs. Copper fires easier than any of the other technologies / chemistries. Don't swallow the hype for E3 / Plus 4 / DiamondFire / etc. (THAT said - I have Bosch +2 plugs in my 1988; they were on sale at RockAuto.)

RwP

 

Hi again Ralph!

Well, I have a lot to learn. Here are pics of my engine with the air cleaner out of the way. Badges on the car say EFI. When I lookup the VIN it does say 1991. I think I have a throttle body. I hope I don't need new heads!





I think I want to lose the AC compressor and associated hoses to make it easy to work on... I highly doubt the AC works and it's just added weight and complication. The serpentine sticker shows you how to route the belt for no AC!

Looks like plug wires need to come out first and then the fun begins!

 

It's not a Magnum. It's the LA 5.2/318.

This complicates matters a bit - it's harder to find LA heads now.

But they're findable.

ARP does sell a fastener set for the LA motor; I'd grab that for the re-assembly; the ARP fasteners are arguably far superior to the "torque to yield" factory fasteners, and they're reusable.

Ignore the heads I linked to; those were for Magnums. Yours is not a Magnum.

RwP

 

Just so you're aware, more often than not, when cars don't have AC, they usually require a different-size serpentine belt. I just looked on RockAuto, and they have a different belt listing for a 91 with AC vs no AC.

Also, depending on how rusty they look, you may want to consider carefully cutting/grinding off the heads of your exhaust manifold bolts/studs and using stud extractors on the remnants after the manifold is off of the head. May save you a lot of pain of drilling them out of the head if they break flush or recessed in the head, or paying a machine shop to do it.

 

Ok Ralph on the screws, I think I already got the ARP kit.

Shaderabbit, my plan was to hit them with some PB blaster for a couple days before even attempting to take them off. Think that will work??

 

Unfortunately, only if you get lucky. I've only worked with the Magnum series engines, but they're cast iron heads with cast iron manifolds like your LA. Maybe call a local machine shop and ask them for a ballpark figure of how much it will cost per stud if they have to drill them out once you get the heads off. If it's affordable, maybe you just PB Blaster them and roll the dice. I have the OTC jig for drilling out manifold studs, and it still sucked, royally. Lot of time, aggravation, and broken and burnt out drill bits. BTW, I did not break the studs, guy I bought the truck off of did.

 

Ok, Thank you for the foresight in the problem.

Hear me out:

IF the threads of the screw are rusted into the head, even if I cut the heads off and leave a stud to grab, how will that help me? Won’t the stud eventually break like the head of the screw would have?

Propane torch for a little heat, PB blast for a few days?? Candle trick? Not trying to argue with you at all, just trying to be proactive and figure out best way to handle... How else can I free up the threads? What would you do with the remaining stud?

Argh.

 

I just watched a video on the stud extractor. I like this idea!!

 

If the bolts are not broken already they should come out. The head of the bolt may be stuck to the manifold, they usually don't get stuck in the head. Most broken bolts are from the manifold warping.

I would just try to crack em loose. Cutting them in the truck will be hard.