New Radiator or something else going on

robbyb20

Well-known member
Oct 2, 2019
145
16
Seattle
Hey Yall,

Have been doing some work on the 97 D1 (oil pressure/tick resolved, head gaskets replaced, etc) but im still coming up against some higher temps than I was about 8 months ago. Im not over heating but im being a bit picky about its running temp, it drives at 192/194 but when sitting at a stop light it climbs to 195/199. With the heat this week (110 ambient), it was driving at 195 and idling at 201. I just got done with a 2200 mile drive and it did really well otherwise.

Im not terribly concerned about the driving temp (although i want to see it back down to 186/188), im more concerned about the idle temp. Its leading me to believe the radiator isnt doing its job efficiently. I have tried 2 different thermostats, a new water pump is on there and ive changed out the hoses recently. Ive done a radiator flush/changed fluid (still running green coolant). Hot air blows hot, no gurgling behind dash. It holds pressure, when i release the cap i can see its not releasing a ton of trapped air/exhaust gases like it would before the headgasket swap. Only thing else I can think of is radiator.

That being said, if it is the radiator, will i see a huge difference between the all metal tank or will the one with the plastic trans/oil coolers do the job just as well?

All metal

Plastic side coolers

Thank you for the help and insight!
Rob
 
Last edited:

mgreenspan

Well-known member
Feb 28, 2005
4,706
122
Briggs's Back Yard
Did you check your fan clutch is working properly? Just try turning it while it’s cold and if it’s really loose then maybe it’s time to replace it. Another more daring test is to stick a newspaper or rolled magazine into the fan while running and see if it stops. 👀

There is a part number cross reference for a heavier duty one someplace on DWeb. But this is the part I believe. This will be cheaper than a radiator replacement on somewhat of a whim.

Hayden Automotive 2786 Premium Fan Clutch https://www.amazon.com/dp/B000C3DD5E/ref=cm_sw_r_cp_api_glt_fabc_59AYDWG29BY5KQFEBQRF

To answer your question though, doubtful. But when anything on the one with plastic breaks it’s guaranteed to need to be completely replaced.
 
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robbyb20

Well-known member
Oct 2, 2019
145
16
Seattle
Did you check your fan clutch is working properly? Just try turning it while it’s cold and if it’s really loose then maybe it’s time to replace it. Another more daring test is to stick a newspaper or rolled magazine into the fan while running and see if it stops. 👀

There is a part number cross reference for a heavier duty one someplace on DWeb. But this is the part I believe. This will be cheaper than a radiator replacement on somewhat of a whim.

Hayden Automotive 2786 Premium Fan Clutch https://www.amazon.com/dp/B000C3DD5E/ref=cm_sw_r_cp_api_glt_fabc_59AYDWG29BY5KQFEBQRF

To answer your question though, doubtful. But when anything on the one with plastic breaks it’s guaranteed to need to be completely replaced.
Thank you for the suggestion. I should have mentioned this was also swapped about 4 months ago with a second on hand as a backup. Both move but do not spin freely, there is a small bit of resistance.

To add to that, the belt is routed just like this.
 

WaltNYC

Well-known member
Mar 3, 2010
579
61
NYC
robby, are those figure with or without the a/c on? At 110 ambient I presume the A/C is on. If you are seeing 194-198 driving in 110 ambient with A/C and 201 at idle your cooling system is working very well.

I am fairly nutty preventing too much heat in the engine as well but we should both bear in mind that 88 deg C was the stock temp and that is 190 deg F.

At idle I start to pucker at 205, kill the A/C at 210, and blast the heat at 215 and over.
 
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robbyb20

Well-known member
Oct 2, 2019
145
16
Seattle
robby, are those figure with or without the a/c on? At 110 ambient I presume the A/C is on. If you are seeing 194-198 driving in 110 ambient with A/C and 201 at idle your cooling system is working very well.

I am fairly nutty preventing too much heat in the engine as well but we should both bear in mind that 88 deg C was the stock temp and that is 190 deg F.

At idle I start to pucker at 205, kill the A/C at 210, and blast the heat at 215 and over.
I appreciate the sound advice. I think its easy to get caught up in the over heating debate and if you read enough here, youll see a wide range of opinions on whats "too hot".

Those driving temps are without AC. With AC on at 110 ambient, i was seeing 204-210. Could still be normal for those ambient temps, it was HOT out!

Ive already received and installed the plastic radiator version and my temps are down to what they were previously. I want to get my old all metal radiator cleaned/serviced as i can already see a huge difference in build quality in the all metal vs plastic.
 

p m

Administrator
Staff member
Apr 19, 2004
14,866
369
56
La Jolla, CA
www.3rj.org
Aluminum radiators (plastic tanks or not) dissipate heat a lot better than copper. They also cause the fan clutches to engage more frequently and for longer periods.
My D1 with a copper radiator with a heavy-duty core runs hotter than all Classic with aluminum.
 

Gordo

Well-known member
Are you running a 180 thermo? That may help. We deal with a lot of heat in FL (not 100 though). I have had a couple plastic radiators. One of our split at the oil cooler and caused oil to get in the water and visa versa. I bought a Nissens one, also plastics and hopefully it doesn't happen again. OUR 96 always sits below half on the coolant gauge. I wouldnt worry at all about 201 or frankly 210 at idle with the ac on in 110 degree heat. anything over that I would shut it off though. If you don't have one I would try the 180 thermo though.
 
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robbyb20

Well-known member
Oct 2, 2019
145
16
Seattle
Aluminum radiators (plastic tanks or not) dissipate heat a lot better than copper. They also cause the fan clutches to engage more frequently and for longer periods.
My D1 with a copper radiator with a heavy-duty core runs hotter than all Classic with aluminum.
My all aluminum one is at the radiator shop (same that Lamorna uses in Seattle) and its been hot tanked, flow tested and some minor cracks fixed up. It was partially blocked but they cleaned it out. Just waiting for the new coat of paint to dry before i can pick it up.

What would be the advantage of a copper core radiator?
 

robbyb20

Well-known member
Oct 2, 2019
145
16
Seattle
Are you running a 180 thermo? That may help. We deal with a lot of heat in FL (not 100 though). I have had a couple plastic radiators. One of our split at the oil cooler and caused oil to get in the water and visa versa. I bought a Nissens one, also plastics and hopefully it doesn't happen again. OUR 96 always sits below half on the coolant gauge. I wouldnt worry at all about 201 or frankly 210 at idle with the ac on in 110 degree heat. anything over that I would shut it off though. If you don't have one I would try the 180 thermo though.
running the standard 88c thermostat. Its in the PNW but i drive all around and the heat in the interior can get up there. The 180 is an easy change so I may do that down the road.