Not over heating but running a little hot.

seventyfive

Well-known member
Jan 3, 2010
4,280
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over there
Maybe I missed it, but did you install a Genuine thermostat yet or are you still running the aftermarket 180F thermostat?
Jimmy, you and I both know if he’s been running 240 degrees and now getting misfires he blew the head gasket. If it was odd cylinders misfiring it’s either hg or cracked block.
 

jymmiejamz

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Dec 5, 2004
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Los Angeles, Ca
Jimmy, you and I both know if he’s been running 240 degrees and now getting misfires he blew the head gasket. If it was odd cylinders misfiring it’s either hg or cracked block.

I haven't been following this closely, so I guess I missed the misfire part. I thought the car was running fine and now after doing all of this work it is running hot. If that is in fact the case, I would still think it is a junk britpart or all makes thermostat causing it to run hot.
 

seventyfive

Well-known member
Jan 3, 2010
4,280
100
over there
Running hot and now misfiring could be completely separate issues...but highly doubt it.
Waaaay back when I had Justin get me a 180 t stat from England, which was actually a parts bulletin upgraded part. He got two, one for me and one for him. I remember he specifically sold the genuine 180 stats...but the price point wasn’t going to sell with our crowd. The aftermarket stuff I never used. Justin was smart in offering genuine parts and leaving it to the consumer What they wanted. Unfortunately people will typically go with the less expensive part...but pay for it eventually
I bought another genuine 180 from him for the gold truck when I rebuilt the entire engine.
Did the 180 stats ever make it to American dealers? This was almost ten years ago when LRNA stopped really supporting discos.
 

jymmiejamz

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Dec 5, 2004
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Did the 180 stats ever make it to American dealers? This was almost ten years ago when LRNA stopped really supporting discos.

I've never seen any bulletin for the North American market for 180F thermostats, and I have a file with every bulletin LRNA published from 87-.07. As far as I know those are only for TD5 and for Gulf states spec trucks.
 

Swedjen2

Well-known member
Sep 12, 2018
594
127
California
Check the length of the head locating pins in the block. I had a mystery leak and found the locating pins were just long enough to prevent the DS head from being torqued properly. It was to the point that when I pulled the DS head, the threads in the block closest to the radiator were stripped to the point I had to get an insert installed.
So check the depth of the pin locating holes and the length of the pins. The block was from one of the better known outfits, but don't know if the P.O. installed the pins or the vendor.
I wonder if that has been a long hidden issue on these engines.
 

discostew

Well-known member
Sep 14, 2010
7,706
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Northern Illinois
Check the length of the head locating pins in the block. I had a mystery leak and found the locating pins were just long enough to prevent the DS head from being torqued properly. It was to the point that when I pulled the DS head, the threads in the block closest to the radiator were stripped to the point I had to get an insert installed.
So check the depth of the pin locating holes and the length of the pins. The block was from one of the better known outfits, but don't know if the P.O. installed the pins or the vendor.
Sounds like somebody shaved the shit out of those heads. I would think the hole got shallow. Who would fuck up so bad that they had to switch out a dowel?
 

malonso123

Active member
May 7, 2019
31
1
Florida
Cracked block leads to blowing hoses, expansion tank, etc. the combustion chamber pressurized the cooling system.

listen to what Willy T said. The needle goes to 12 o’clock at approximately 130 degrees and doesn’t rise until 230 if I remember correctly.
I plumbed my coolant temp sender at the output before the thermostat, my gauges (oil temp, oil pressure, coolant temp, and coolant pressure) were marked numerically so I actually knew what the temps and pressure was. That’s when I noticed the the actual temperature relative to the factory gauge.
I clocked the gauges so the temp and coolant pressure needles were at 12 o’clock at proper temp and pressure.
Any time those needles were not at 12 o’clock I knew to shut down.

typically 240 degrees is getting into head gasket failure range.
You should start with a genuine thermostat like jimmy said.

I ran a block test. tested for exhaust in coolant. no issues. i think i am going to break down the whole cooling system. i am leaning towards a clog or a defective water pump. we will see.
 

malonso123

Active member
May 7, 2019
31
1
Florida
I haven't been following this closely, so I guess I missed the misfire part. I thought the car was running fine and now after doing all of this work it is running hot. If that is in fact the case, I would still think it is a junk britpart or all makes thermostat causing it to run hot.
I ran a block test. tested for exhaust in coolant. no issues. i think i am going to break down the whole cooling system. i am leaning towards a clog we will see.
 

Stocksuspension66

Well-known member
Mar 26, 2020
104
9
California
Late to the party. So no leaks. Passes block test but has misfires. Quick ? Does it misfire on cold start up? I would check radiator efficiency. You can use a fancy temp gun or your hand. I would place a fan in front of radiator and see if that helps. You can remove the hoses and flush it out as well. And definitely install a factory thermostat as previously mentioned. Also check temp at heater core hoses.

Side note: I remember one time one of my apprentices finished up head gaskets on a lg405 and I could hear the aux fan on at idle. I shut it off and checked for leaks. Checked for heat at heater. Checked thermostat. Block tested. Everything was good until I found a giant cardboard in front of the radiator. Box was there to prevent “mishaps”. Just make sure you cross your t’s and dot your i’s.
 

jymmiejamz

Well-known member
Dec 5, 2004
6,008
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Los Angeles, Ca
Side note: I remember one time one of my apprentices finished up head gaskets on a lg405 and I could hear the aux fan on at idle. I shut it off and checked for leaks. Checked for heat at heater. Checked thermostat. Block tested. Everything was good until I found a giant cardboard in front of the radiator. Box was there to prevent “mishaps”. Just make sure you cross your t’s and dot your i’s.

I remember years ago in the shop we had an LR3 that would intermittently overheat. It took forever for us to duplicate it. Finally the tech got to the point where he determined the radiator (or fan, can't remember) was the problem. When he pulled the fan there was a piece of plywood in there left from an independent shop. I was pretty amazed how long it would take to overheat in the summer in Virginia.
 
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discostew

Well-known member
Sep 14, 2010
7,706
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Northern Illinois
The Disco2 radiator is so fragile. I dropped a 1/4 drive 10mm socket and broke one of the tubes in the core. Then I started putting a piece of cardboard in there to protect it. I left one in once, I realized it before I gave it back to the customer. So I cut a new piece that stuck way up high and folded over the front of the grill.
I recommend protecting these radiators when your working on the front of the engine. I would just make it really hard to forget
 
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malonso123

Active member
May 7, 2019
31
1
Florida
Update. I went ahead and tore it down to the heads again and noticed my head bolts were not to difficult to loosen. i measured the torque on the bolts and it averaged around 90FT/LBs. is that what is expected? does anyone know what the torque averages? Also I did not have steam cleaned cylinders and gaskets were on correct and look great. any feed back would be appreciated.
 
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_ExpeditionMan

Well-known member
Dec 11, 2017
295
34
Texas
You already tore it down, but I did not see anyone ask here... are you running your A/C while reaching these temps? Or are you reaching these temps with the A/C off? Are your secondary electric fans (in front of the condenser) turning on when you hit the A/C button? Or after you exceed 210F?
 

malonso123

Active member
May 7, 2019
31
1
Florida
You already tore it down, but I did not see anyone ask here... are you running your A/C while reaching these temps? Or are you reaching these temps with the A/C off? Are your secondary electric fans (in front of the condenser) turning on when you hit the A/C button? Or after you exceed 210F?
Yes with AC on and the fan turns on at 210F
 

malonso123

Active member
May 7, 2019
31
1
Florida
Head bolts at 90 sounds very low. To release mine, I needed a 2 1/2 ft bar and a lot of grunt.
thats what i remembered from taking them off originally. so i don't understand why they would be so low after the two 90 degrees . and i waited an hour between 90's. technically i torqued them to 15 ft/lbs first then the two 90's.