Need help - Oil Temps as high as 256 deg
05-20-2017, 10:12 AM
#21
Safety Car
Using 10W30 for your 85 4+3 is perfect. Using a heavy weight oil for 1000 miles and then changing to synthetic oil sounds like something he made up. That "fix" won't do anything. 
Definitely do not use synthetic oil in it. Early C4's were never designed for synthetic oil. Waste of money and it WILL leak. A puff of blue smoke on start up most likely indicates bad valve stem seals. You probably have the original seals in it and they dry out and get hardened. Oil seeps by them and gets burned off on start up. As far as your oil temperature reading high, I'd change the oil temp sensor first and see what readings you get.
05-20-2017, 10:18 AM
#22
Le Mans Master
your mechanic needs to be changed. Using 10w30 for your 85 4+3 is perfect. Using a heavy weight oil for 1000 miles and then changing to synthetic oil sounds like something he made up. That "fix" won't do anything. Definitely do not use synthetic oil in it. Early c4's were never designed for synthetic oil. Waste of money and it will leak. A puff of blue smoke on start up most likely indicates bad valve stem seals. You probably have the original seals in it and they dry out and get hardened. Oil seeps by them and gets burned off on start up. As far as your oil temperature reading high, i'd change the oil temp sensor first and see what readings you get.
Using 10w30 for your 85 4+3 is perfect. Using a heavy weight oil for 1000 miles and then changing to synthetic oil sounds like something he made up. That "fix" won't do anything. Definitely do not use synthetic oil in it. Early c4's were never designed for synthetic oil. Waste of money and it will leak. A puff of blue smoke on start up most likely indicates bad valve stem seals. You probably have the original seals in it and they dry out and get hardened. Oil seeps by them and gets burned off on start up. As far as your oil temperature reading high, i'd change the oil temp sensor first and see what readings you get.
05-20-2017, 10:43 AM
#23
Melting Slicks
Your mechanic needs to be changed. Using 10W30 for your 85 4+3 is perfect. Using a heavy weight oil for 1000 miles and then changing to synthetic oil sounds like something he made up. That "fix" won't do anything. Definitely do not use synthetic oil in it. Early C4's were never designed for synthetic oil. Waste of money and it WILL leak. A puff of blue smoke on start up most likely indicates bad valve stem seals. You probably have the original seals in it and they dry out and get hardened. Oil seeps by them and gets burned off on start up. As far as your oil temperature reading high, I'd change the oil temp sensor first and see what readings you get.
Using 10W30 for your 85 4+3 is perfect. Using a heavy weight oil for 1000 miles and then changing to synthetic oil sounds like something he made up. That "fix" won't do anything. Definitely do not use synthetic oil in it. Early C4's were never designed for synthetic oil. Waste of money and it WILL leak. A puff of blue smoke on start up most likely indicates bad valve stem seals. You probably have the original seals in it and they dry out and get hardened. Oil seeps by them and gets burned off on start up. As far as your oil temperature reading high, I'd change the oil temp sensor first and see what readings you get.Modern day 10w30 oils have no where the zinc needed for a flat tapped engine.
I run full synthetic oils in everything including an all my original 1971 Mach 1 and my 57 Chevy I had. Guess what no leaks anywhere in anything. Whoever started that myth needs their head examined. If these two didn't leak and yours does YOU HAVE ISSUES ELSEWHERE other than oil I promise.
As far as wasting money a jug of 5 qts of Mobil 1 0w40 is under $26 at Wal-Mart. If you cant swing that you really need to be driving a Spark brother.
Last edited by Cjunkie; 05-20-2017 at 10:48 AM.
05-20-2017, 11:16 AM
#24
Safety Car
This post is
Modern day 10w30 oils have no where the zinc needed for a flat tapped engine.
I run full synthetic oils in everything including an all my original 1971 Mach 1 and my 57 Chevy I had. Guess what no leaks anywhere in anything. Whoever started that myth needs their head examined. If these two didn't leak and yours does YOU HAVE ISSUES ELSEWHERE other than oil I promise.
Modern day 10w30 oils have no where the zinc needed for a flat tapped engine.
I run full synthetic oils in everything including an all my original 1971 Mach 1 and my 57 Chevy I had. Guess what no leaks anywhere in anything. Whoever started that myth needs their head examined. If these two didn't leak and yours does YOU HAVE ISSUES ELSEWHERE other than oil I promise.
It must be nice to have money to waste. "Mythical"? 
05-20-2017, 11:20 AM
#25
Le Mans Master
This post is
Modern day 10w30 oils have no where the zinc needed for a flat tapped engine.
I run full synthetic oils in everything including an all my original 1971 Mach 1 and my 57 Chevy I had. Guess what no leaks anywhere in anything. Whoever started that myth needs their head examined. If these two didn't leak and yours does YOU HAVE ISSUES ELSEWHERE other than oil I promise.
As far as wasting money a jug of 5 qts of Mobil 1 0w40 is under $26 at Wal-Mart. If you cant swing that you really need to be driving a Spark brother.
Modern day 10w30 oils have no where the zinc needed for a flat tapped engine.
I run full synthetic oils in everything including an all my original 1971 Mach 1 and my 57 Chevy I had. Guess what no leaks anywhere in anything. Whoever started that myth needs their head examined. If these two didn't leak and yours does YOU HAVE ISSUES ELSEWHERE other than oil I promise.
As far as wasting money a jug of 5 qts of Mobil 1 0w40 is under $26 at Wal-Mart. If you cant swing that you really need to be driving a Spark brother.
How much engine work has been done in those cars before using synthetic??
Starting to use synthetic in a 100K engine is asking for leaks where there had been none before.
05-20-2017, 11:22 AM
#26
Le Mans Master
The guy doesn't have a clue.
05-20-2017, 12:50 PM
#29
Team Owner
Pro Mechanic
All brand name oils...and even virtually all no-name/store brand oils are way better than good enough.
EDIT: HERE IS A GOOD READ, that replaces lore, with science and objective information. Have a look!
.
Last edited by Tom400CFI; 05-20-2017 at 01:29 PM.
05-20-2017, 02:43 PM
#31
Racer
This is some bad, misinformation. OP, please ignore this post.
All brand name oils...and even virtually all no-name/store brand oils are way better than good enough.
EDIT: HERE IS A GOOD READ, that replaces lore, with science and objective information. Have a look!
.
All brand name oils...and even virtually all no-name/store brand oils are way better than good enough.
EDIT: HERE IS A GOOD READ, that replaces lore, with science and objective information. Have a look!
.
Just a note though, his recommendation on the Mobil 1 High Mileage is no longer operative. At least per the Mobil 1 chart I printed out today. https://mobiloil.com/en/faq/ask-our-...r-classic-cars (See answer to question and link to chart)Mobil 1 High Mileage is now rated SN, not SL as in the post. Though to be fair he did indicate that the rating may change over time and it has. Now rated at 800ppm phosphorus and 900ppm zinc. Still not bad but not the >1100 it was.
Mobil has a new Mobil 1 FS 0W-40 that is rated at 1000ppm phosphorus and 1100ppm zinc that might be a good oil for flat tappet C4's.
Last edited by Weck86; 05-20-2017 at 02:45 PM. Reason: link to Mobil 1
05-20-2017, 03:35 PM
#33
Melting Slicks
The Mach1's engine hasn't been touched since it left the factory and the 57 to the best of my knowledge wasn't touched.
You can start synthetic at any time.
05-20-2017, 03:35 PM
#34
Melting Slicks
That was a good read! Just a note though, his recommendation on the Mobil 1 High Mileage is no longer operative. At least per the Mobil 1 chart I printed out today. https://mobiloil.com/en/faq/ask-our-...r-classic-cars (See answer to question and link to chart)
Mobil 1 High Mileage is now rated SN, not SL as in the post. Though to be fair he did indicate that the rating may change over time and it has. Now rated at 800ppm phosphorus and 900ppm zinc. Still not bad but not the >1100 it was.
Mobil has a new Mobil 1 FS 0W-40 that is rated at 1000ppm phosphorus and 1100ppm zinc that might be a good oil for flat tappet C4's.
Just a note though, his recommendation on the Mobil 1 High Mileage is no longer operative. At least per the Mobil 1 chart I printed out today. https://mobiloil.com/en/faq/ask-our-...r-classic-cars (See answer to question and link to chart)Mobil 1 High Mileage is now rated SN, not SL as in the post. Though to be fair he did indicate that the rating may change over time and it has. Now rated at 800ppm phosphorus and 900ppm zinc. Still not bad but not the >1100 it was.
Mobil has a new Mobil 1 FS 0W-40 that is rated at 1000ppm phosphorus and 1100ppm zinc that might be a good oil for flat tappet C4's.
05-20-2017, 07:52 PM
#35
Burning Brakes
What ex-x-fire said. Coolant system needs attention. OIL, not 0w40, 10w40 high mileage Mobil 1, synthetic oil can handle high temps better than conventional oil, this is not a new engine 10w40 would be fine, but 260 oil temp is to high for any street engine. Get coolant temps down and check to see if oil temps fallow.
The following users liked this post:
FOURSPEEDVETTE (05-21-2017)
05-20-2017, 11:38 PM
#36
Instructor
Thread Starter
Figured part of it out
while I was removing the throttle body for cleaning I found my coolant leak. The coolant hose that goes from the block to the underside of the throttle body was mush. Leaking from 5-6 different spots. While nobody local has the molded pipe, the guys at Summit Racing recommended E-Z Coil. It takes a standard straight coolant line from a parts store and lets you bend it without kinking it. Best $5.31 I've ever spend. Was able to take it out tonight and coolant stayed below 200 with all city driving. Oil temp stayed 10 degrees below coolant temp until the last mile, then it jumped above by 8 degrees. Will replace the oil temp sensor this week and see what happens.
Thanks for for all the input. Yes, my "mechanic" is no longer my mechanic. The owner of the shop he works in told me to ignore 99% of what his guy says. He's basically good for brake jobs and tire changes on modern cars. I should have known better.
My oil is still clean after 2 weeks. I'm not burning oil as it's still right up to the full line on the dipstick.
After I change the oil temp sensor, I'll take a look at the 4+3 (which right now is a 4 only). I wonder if the high RPM is part of the oil temp issue? is the high rpm due to low fluid in the trans or rear end?
to be continued...........
Thanks for for all the input. Yes, my "mechanic" is no longer my mechanic. The owner of the shop he works in told me to ignore 99% of what his guy says. He's basically good for brake jobs and tire changes on modern cars. I should have known better.
My oil is still clean after 2 weeks. I'm not burning oil as it's still right up to the full line on the dipstick.
After I change the oil temp sensor, I'll take a look at the 4+3 (which right now is a 4 only). I wonder if the high RPM is part of the oil temp issue? is the high rpm due to low fluid in the trans or rear end?
to be continued...........
Last edited by Buckeye88; 05-20-2017 at 11:39 PM.
05-20-2017, 11:53 PM
#37
Burning Brakes
Oil temps of 5-15 degrees above coolant temps are normal when engine has been run at operateing temp for 25-35 minutes on highway, coolant 185--oil 200 normal, run it hard ,coolant 190---oil 215 normal. It takes oil longer to reach full temp than coolant.
Last edited by A Peter C4; 05-21-2017 at 12:08 AM.
05-21-2017, 12:10 AM
#38
Safety Car
while I was removing the throttle body for cleaning I found my coolant leak. The coolant hose that goes from the block to the underside of the throttle body was mush. Leaking from 5-6 different spots. While nobody local has the molded pipe, the guys at Summit Racing recommended E-Z Coil. It takes a standard straight coolant line from a parts store and lets you bend it without kinking it. Best $5.31 I've ever spend. Was able to take it out tonight and coolant stayed below 200 with all city driving. Oil temp stayed 10 degrees below coolant temp until the last mile, then it jumped above by 8 degrees. Will replace the oil temp sensor this week and see what happens.
Thanks for for all the input. Yes, my "mechanic" is no longer my mechanic. The owner of the shop he works in told me to ignore 99% of what his guy says. He's basically good for brake jobs and tire changes on modern cars. I should have known better.
My oil is still clean after 2 weeks. I'm not burning oil as it's still right up to the full line on the dipstick.
After I change the oil temp sensor, I'll take a look at the 4+3 (which right now is a 4 only). I wonder if the high RPM is part of the oil temp issue? is the high rpm due to low fluid in the trans or rear end?
to be continued...........
Thanks for for all the input. Yes, my "mechanic" is no longer my mechanic. The owner of the shop he works in told me to ignore 99% of what his guy says. He's basically good for brake jobs and tire changes on modern cars. I should have known better.
My oil is still clean after 2 weeks. I'm not burning oil as it's still right up to the full line on the dipstick.
After I change the oil temp sensor, I'll take a look at the 4+3 (which right now is a 4 only). I wonder if the high RPM is part of the oil temp issue? is the high rpm due to low fluid in the trans or rear end?
to be continued...........
05-21-2017, 05:08 AM
#40
Drifting
It was but it's now Quaker Steak and Lube. Not as good as McGarveys. Any time you want give me a call and drop by. We can grill out and bust some knuckles on your car. We can always take the car up to my work and use the lifts and alignment rack and all the flush machines. I'm happy to help you get the car where you want it!!
The following users liked this post:
mazdaverx7 (05-21-2017)