85 2m4 SE / 2.5 Temperature Issues (Page 7/7)
cartercarbaficionado MAY 06, 06:36 PM

quote
Originally posted by 82-T/A [At Work]:
Thanks CarterCarbs... I may have to take you up on that. Do you have a need for a perfect 88 cyl head? It's just sitting on the floor of my garage taking up space.

But yeah... I don't think it's the head, but could be the gasket. It could ALSO be the intake manifold... it was pitted a lot by the coolant passage, so it's possible that's happening. I could remove the plugs and check to see if one of them is SUPER clean, that would basically answer my question if I have a head gasket leak, among other things.

It has lots of power though, really runs amazing.

Is it bad to re-torque the head bolts? Just curious... they're already on the car of course... but if I take a torque wrench to them again (90 foot pounds I think?)... will I destroy anything?


i retorqued my 289 ford a few times and it was ok? if you need another 84 manifold i got that too. the tb is going in the parts stash since it needs a full rebuild but the intake wasnt bad but we were not spending another dime on dukes for our 84 (if you really want i will trade a 3800 for our entire freshly broken in duke and its automatic and maybe a spare automatic as well if i can find ANNNY 4 or 5 speeds for a decent amount which is like 100 bucks)
as for the 88 head? yeah i could probably put it to good use for the upcoming camaro or 3400 swap we are doing since i have a broken 2.8l head, if its a duke head i know somebody who probably wants a spare
82-T/A [At Work] AUG 22, 02:19 PM
Hey guys,

I wanted to hit this topic again, and give an update. My daughter had been having some issues with the Iron Duke that she rebuilt. It ran FANTASTIC... loads of power, just absolutely performed brilliantly. The only problem is, she was continuously getting coolant leaks. In several instances, coolant would leak past the hoses at scorching temperatures, and in some cases would blow out entire gaskets. We even blew the seams out of a brand new radiator (which I posted further above). Compound this by the fact that I had a temperature sending unit that was giving outrageous temperature readings for the engine.

We eventually discovered that the temperature sending unit was crap (even though it was brand new), and bought a new one. With the new one installed, the temperature was fantastic... and was consistent with what I'd measured with the infrared device shown on either the first or second page. The car would idle perfectly, but then when we'd give it some gas (blip the throttle)... the car would puff a cloud of white smoke after it had warmed up. Normal driving, the car was fine. It had plenty of power, and even under spirited driving it drove fantastic. But when it was allowed to sit after heavy driving, it would give a big puff of white smoke. I ran through all kinds of scenarios and thought maybe it was either a blown head gasket, or a cracked cyl head. The thing is, I never saw any oil and water mixing... so that's good.

Turns out, the cyl head is cracked. I haven't verified it, but I talked to the machine shop (who has several Iron Duke engines in the back that he showed me, all from Fieros, and one from a Jeep), he said they have a tendency to crack between the valves... in which case under very calm or normal operation... there's no leak. Under heavy load, it adds pressure to the cooling system (which can blow out seals), but then when not under load (but running hot), coolant then dumps into the combustion chamber... causing the white puff of smoke. He also said that by the nature of that kind of crack, it often won't show up on a hydrocarbon test of the cooling system either.


A couple of months ago, CarterCarbsAfficionado was nice enough to sell me a used Iron Duke (1986) cyl head. I just got it back from the machine shop, and they magnafluxed it and said everything was great (the other machine shop didn't do that to the original cyl head). I'm happy with this outcome because my daughter was really concerned that she had done something wrong in the assembly, and was kind of discouraged... so she's really happy to know that it's not what she did, but just a crack in the cyl head that the previous machine shop didn't detect (note, we properly burped the system when we started it).


I'm going to put the new cyl head on for her, as I promised (so she doesn't have to re-do this work herself), but she's going to be installing a new exhaust shorty header (an original Fiero Store item that we bought used on eBay), and the bored stock throttle body and stock intake manifold in a later video. We're looking to get ~100hp from this engine, and we'll probably dyno it once we've worked out all the kinks... just for fun.
Frenchrafe AUG 23, 04:33 AM
Hi Todd,
You've never tried a product like Holts block weld?
I did a video a couple of years or so ago with the steaming issues I had with the turbo 3800 motor:

https://youtu.be/TluYuWvYEBw

It been fine ever since so no need to rebuild the motor.(Again!)

Cheers,
Rafe

------------------
"Turbo Slug" - '87 Fiero GT. 3800 turbo. - The fastest Fiero in France! @turboslugfiero
https://youtu.be/hUzOAeyWLfM

82-T/A [At Work] AUG 26, 11:55 AM

quote
Originally posted by Frenchrafe:

Hi Todd,
You've never tried a product like Holts block weld?
I did a video a couple of years or so ago with the steaming issues I had with the turbo 3800 motor:

https://youtu.be/TluYuWvYEBw

It been fine ever since so no need to rebuild the motor.(Again!)

Cheers,
Rafe





Wow, that's amazing how that worked!

I've used some of those things in the past, but I'd always frowned upon them as I viewed them as last-ditch efforts before you junk the motor, so to speak. But I'd totally have tried it if I had known. That's awesome.

I already have the completely reconditioned cyl head, so I'm going to put that on for her, but I'm going to keep that in mind for the Corvette... which I think may have a SLIGHT leak (no where near as bad).


Thanks!!!
82-T/A [At Work] OCT 24, 02:36 PM
Just wanted to post a final update on this, in case anyone searches up these symptoms and has a similar problem. I mentioned in the last post (above) that the machine shop thought that (what I was telling them) the cyl head sounded like it had a crack in it.

I just went to pick up some exhaust manifolds for the Corvette, and check on the intake manifold, and they had the update for the cyl head ready for me... they verified that it was in fact cracked. Here are some pictures:











So, just to confirm what I'm showing here, it's a crack on the exhaust port of the #3 cyl, which is directly next to a water port in the cyl head.

What he said to me, without even me saying anything is that this is a crack that would only show up when you're driving around, or putting it under load. He said that under idle, it would show absolutely no signs of being cracked, that it wouldn't even burn coolant at idle, but as you start driving it around, it'll switch between sucking in coolant and forcing exhaust gasses into the coolant chambers.

So... this was most likely my problem!


I still need my intake manifold back. I had them bore it out, but he had written 56mm on it, but I needed it bored out too 46 mm. He didn't want to do it because he felt 56 was too much. He had already bored it out to 45mm but waited because he didn't want to ruin the intake. I talked to him again and asked him to bore it out to 50mm, becuase I have a Holley TBI unit that's 50mm, and maybe AJ can test the modified TBI we have (45.5mm), and the Holley one (50mm). So, I have options. He said he would be ready by next Friday.
82-T/A [At Work] NOV 23, 07:21 PM
Just wanted to update this thread one last time in case anyone else sees this and gets discouraged.

We got the head back on a while ago, but were waiting for the intake manifold back from the machine shop (we were having it bored out).

The cyl head from CarterCarbsAfficionado did the trick. We burped the cooling system and did a few other things, and then ran it a few times to make sure everything was good... and oh my gosh... it runs so nice... I mean, really, really nice. It's just a dream to drive. It doesn't even sound like you're typical Duke motor. With everything she's done to it, it runs incredibly smooth. There's no clackety sounds, and it's just smooth power. The shifts through the gears are fantastic. The only thing is it's hard too get into first, but shifting to all the other gears is just amazing. Like... I am so impressed with it.

The crappy thing is that the front suspension is still completely shot, I mean, completely shot... and we haven't tackled that yet. And... the doors don't have bump stops, so ever bump, the doors bang. But the rest of the car is immaculate. We're not sure what we want to do next... the doors, or the front suspension.
82-T/A [At Work] NOV 24, 01:08 PM
Ok... one more update. I'm distracted since it's so close to the holidays, and taking a break from proposal writing for work, I went into the garage to check the coolant level after driving the Fiero around for over an hour.

I removed the thermostat cap, and low and behold... it was full. It actually spilled a little. This is good news as it means I've properly burped the system, and any additional coolant it needed, it stole from the overflow tank (which has a small leak at the seam, incidentally, so I'm going to have to remove it and fix it).

But everything was great. I always run a car without a thermostat after working on the cooling system, just to make sure all the bubbles are out, but I went ahead and installed the 180-degree thermostat.


Anyway, take away is that it confirms for me that there's no leaks anywhere in the cooling system, and man... it makes me so happy after months and months and months of trying to figure out what was going on.