engine and drivetrain Oil related ? for JimK

[Guest Anonymous]

Since I rebuilt the engine in My 72 tii about 18 months ago. During that time, I have changed the oil at least 4 times. The first two changes used conventional Castrol 20w50 and the changes were at 300 miles and then 750 miles to insure removal of metal particulates discharged by the new engine. For the past 7,000 miles I have used Amsoil 20w50 without any noticiable issues. (Changed at 3500 miles). I had planned to extend the oil change intervals by double.

This past month the car has been driven in very nasty stop and go traffic with extremely arid and high temperatures in the Southwest. The temperature gauge has always acted up a bit despite preventative grounding measures. On several successive days, the gauge crept up to below the red but not higher. The radiator did not boil over or loose coolant, but the slight amount of pinging leads me to believe the temperature gauge was correct. On one occasion, I pulled off the side of the road and sped the idle up getting the temp gauge to move downward a little and then I shut the engine down. When I tried starting the engine 20 minutes later, it turned over with much difficulty, but the engine eventually began to run as it did before although it is possible it is running a tiny bit rougher.

I have since driven the car for a week and it seems okay and doesn't smoke or show signs of abnormal wear BUT the engine does not seem to turn over as quickly as it did before. (I have an M3 starter) This suggests to me something internally has changed and the tolerances may be slightly tighter or out of whack. In any case, this leads me to my question. Had I been using conventional motor oil, I would not have hesitated to change the oil immediately for fear that it had now been compromised by severe heat. Do I need to change the Amsoil or should I just do it as a matter of preventative maintenance?

TIA

[jimk]

If you want to know for sure if it handled the heat, sent a sample for analysis, but I have to say you can't hurt the stuff with heat. I've seen cars with 1 qt left in the pan, others that threw a fan belt and drove til it dropped but never hurt the bottom end, the oil was ok.

[Guest Anonymous]

Thanks for the quick reply! Frankly, oil analysis would not be particularly helpful to me, because if anything is turned up, there is nothing I can do to put things as they were. Conversely, if there are no positives, it provides a little peace of mind, but I intend to drive the car either way since my daily driver was recently cracked up.

Do you recommend I change the oil anyway? Or just the filter? Or neither?

I have read many of your earlier posts on this subject. Given the potential wear, do you still recommend going with 10W40 instead of the heavier weight? Would the heavier weight afford more protection for engines prone to running at higher operating temperatures?

Thank you again.

[c.d.iesel]

I WOULD CONFIRM THE IGNITION TIMING FIRST

wrong timing will cause, difficult cranking, over heating,

motor/cumbustion noises, ................

or bad starter motor - when hot - resistance increases

and poor cranking - - to no cranking results -

suspect a bum rebuilt starter ?

brand of 20w/50 oil does not cause any of your symptoms

[Mike Self]

a complete rebuild. Ran dino oil thru two quick changes when the engine was new, then started using AMSOL 20w-50, lengthing oil change period to 6-7k miles (previously 4k with regular oil.)

Other than the oil pressure being a little lower with the synthetic than previously with conventional 20w-50, I've seen no difference. And since the whole engine--including the oil pump--is new, I don't know if the lower pressure is a synthetic oil attribute or whether it's the new pump.

So far, so good. Engine runs like a top.

mike

[Guest Anonymous]

CD: You misinterpreted the gist of my post.

So far as I can tell, the engine runs fine. Something clearly tightened up after the engine heated. Since that time, the engine does not seem to start as quickly. THis could just be my biased perception. The timing is slightly advanced as it has been since the rebuild.

My concern is the reliability of the oil used. Just as after a race most teams change the vital fluids, I was prepared to do so here. It was only because of the use of synthetic oil that I have resisted what seems so obvious to me (at least with conventional motor oils).

[Guest Anonymous]

Although I can't say I paid very close attention, I haven't noticed a difference in oil pressure between the two oils. I have noticed a difference in color and as strange as I may seem, the synthetic oil seems lighter or thinner than the conventional oil. I have no empirical data to support this, mind you.

Given JimK's prescription for 10W40, is there any reason you are still running 10 or 20W50? In my case, I assumed the extra weight couldn't hurt. On the other hand, our new Honda gets by on 10W30. But I have no idea how long this will last. When I opened up the 30+ year old 02 (240K mi) weened only on conventional motor oil, there were slight hone marks on the cylinder walls. To be fair, there was a fair amount of wear at the top of the cylinder walls leaving a ridge that had to be reamed.

[jimk]

Do you recommend I change the oil anyway? Or just the filter? Or neither?

I have read many of your earlier posts on this subject. Given the potential wear, do you still recommend going with 10W40 instead of the heavier weight? Would the heavier weight afford more protection for engines prone to running at higher operating temperatures?

Thank you again.

No change needed, no filter either.

I run 10w-40, 20w-50 just sucks up fuel. Amsoil 10w-40 will give you all the protection you need. I ran it when I had a turbo on my car. Oil analysis showed ok for further use and no abnormal wear at 12,000mi on the oil with the turbo. Did the same with a Buick turbo I had, same results.

[jimk]

Although I can't say I paid very close attention, I haven't noticed a difference in oil pressure between the two oils. I have noticed a difference in color and as strange as I may seem, the synthetic oil seems lighter or thinner than the conventional oil. I have no empirical data to support this, mind you.

It appears thinner at room temperature because it doesn't thicken as much at colder than operating temperature. At 200F it's the same viscosity.

The only time a synthetic will be thinner than the same grade dino is if it is a cheap one that has sheared back and didn't stay in grade. Some grades of Redline gearlube suffer from this.

[Guest Anonymous]

No change needed, no filter either. I run 10w-40, 20w-50 just sucks up fuel. Amsoil 10w-40 will give you all the protection you need. I ran it when I had a turbo on my car. Oil analysis showed ok for further use and no abnormal wear at 12,000mi on the oil with the turbo. Did the same with a Buick turbo I had, same results.

I have been in a similar quandry as to when it is better to change the oil. I have always felt it cheap insurance to change the oil when in doubt. But that is relatively easy if speaking of conventional motor oils. I am aware that oil analysis is the proof in the pudding, but I wonder if there aren't any other tell tale signs of when Amsoil or other well know synthetics could benefit from a change. Are there obvious cues in the color or smell of the oil as is the case with Automatic transmission fluid? As an ignorant observation, I can use Amsoil and withing 1000 miles it turns almost black. I can go another 1000 miles on Valvoline synthetic before it turns darker and looses its "fresh" sweet smell. Yes, I understand that a dark oil may only mean it is performing its normal function in keeping within suspension combustion by-products.

So, is there anything to look or sniff for, or is this just an unestablished popycock?

Thanks, I enjoy reading your thoughtful responses.

(I also thought I previously posted this followup, but since I cannot find it, it may be somewhere else in cyberspace. So my appologies.)

[jimk]

No change needed, no filter either. I run 10w-40, 20w-50 just sucks up fuel. Amsoil 10w-40 will give you all the protection you need. I ran it when I had a turbo on my car. Oil analysis showed ok for further use and no abnormal wear at 12,000mi on the oil with the turbo. Did the same with a Buick turbo I had, same results.

I have been in a similar quandry as to when it is better to change the oil. I have always felt it cheap insurance to change the oil when in doubt. But that is relatively easy if speaking of conventional motor oils. I am aware that oil analysis is the proof in the pudding, but I wonder if there aren't any other tell tale signs of when Amsoil or other well know synthetics could benefit from a change. Are there obvious cues in the color or smell of the oil as is the case with Automatic transmission fluid? As an ignorant observation, I can use Amsoil and withing 1000 miles it turns almost black. I can go another 1000 miles on Valvoline synthetic before it turns darker and looses its "fresh" sweet smell. Yes, I understand that a dark oil may only mean it is performing its normal function in keeping within suspension combustion by-products.

So, is there anything to look or sniff for, or is this just an unestablished popycock?

Thanks, I enjoy reading your thoughtful responses.

(I also thought I previously posted this followup, but since I cannot find it, it may be somewhere else in cyberspace. So my appologies.)

Chedd,

If your oil is "black" you have choke or overly rich problems.

I use a Northern Instruments "Lube Safe" instrument to tell if oil has changed from new condition w/o having to stand the oil analysis expense or time lag for results. By changed I mean a chemical change, fuel or foreign particle contamination. The instrument is so sensitive that if you pass your finger near the sample, the needle will move.

BTW, Amsoil ATF will never smell burnt, it's flashpoint is way higher. It passes Ford's high temp test at 3 times the test duration.

[Guest Anonymous]

I may have overstated the "black" color of the oil but it definitely turns darker than some of the other oils I have tried. Of course Amsoil seems to be naturally darker than some, e.g., Quaker State, Valvoline.

Where does one obtain the analyzer you mentioned? And, how many $$$?

Thank you again for your posts.

[jgerry2002]

More importantly I hope you upgraded the radiator and added the biggest electric auxiliary fan that you can fit in your car. A 14" Permacool will work without AC.

I would not worry about the oil much. Its quality stuff.

[jimk]

I may have overstated the "black" color of the oil but it definitely turns darker than some of the other oils I have tried. Of course Amsoil seems to be naturally darker than some, e.g., Quaker State, Valvoline.

Where does one obtain the analyzer you mentioned? And, how many $$$?

Thank you again for your posts.

Tonight I searched for it on the Web. Seems like Northern Instruments is now called Northern Technologies International Corp and I can't find info on the instrument. My hard copies of the info sheet are dated 1998. I think they quit the product. If anyone comes across a analyzer called LubeSafe, that's it. I have a model N1-3A.

[Harv]

If anyone comes across a analyzer called LubeSafe, that's it. I have a model N1-3A.

Jim, you are way too cool! (That was NOT in a sarcastic tone)

John