I've searched numerous times to no avail but I'm sure this has been covered. I have a 97 7.3 diesel with 140k and the original owner used conventional oil since day one. A respected diesel mechanic in the area claims switching to synthetic oil now will cause problems due to removing deposits and resulting in leaks and other issues and claims that he has seen this before. I find it hard to believe but since he is an excellent diesel mechanic I want some advice. I bought this truck and am adding an FS2500 bypass filter and was going to run Amsoil HD diesel and marine oil with extended oil change intervals.
Help with topics on switching to synthetic
- Thread starter mrvmax
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dnewton3
Staff member
Your "excellent diesel mechanic" is generally wrong. Presuming the former owner used quality HDEOs in routine OCIs, then there's not really a reason to suspect massive "deposits" to remove in the first place. Seals were an issue WAY back in the day, but those concerns were addressed long ago by choosing better seal materials and altering chemistry of the lubes.
Nothing wrong with your plan, as long as you monitor the extended OCIs with UOAs and other common sense observations.
Nothing wrong with your plan, as long as you monitor the extended OCIs with UOAs and other common sense observations.
Originally Posted By: dnewton3
Your "excellent diesel mechanic" is generally wrong. Presuming the former owner used quality HDEOs in routine OCIs, then there's not really a reason to suspect massive "deposits" to remove in the first place. Seals were an issue WAY back in the day, but those concerns were addressed long ago by choosing better seal materials and altering chemistry of the lubes.
Nothing wrong with your plan, as long as you monitor the extended OCIs with UOAs and other common sense observations.
Agreed; I've switched over 2 vehicles with 86k and over 100k miles, only has some seepage near the rear main seal, which dried up during the first OCI.
Your "excellent diesel mechanic" is generally wrong. Presuming the former owner used quality HDEOs in routine OCIs, then there's not really a reason to suspect massive "deposits" to remove in the first place. Seals were an issue WAY back in the day, but those concerns were addressed long ago by choosing better seal materials and altering chemistry of the lubes.
Nothing wrong with your plan, as long as you monitor the extended OCIs with UOAs and other common sense observations.
Agreed; I've switched over 2 vehicles with 86k and over 100k miles, only has some seepage near the rear main seal, which dried up during the first OCI.
If you were in a cold climate, I would say the HPOP would be happier in the winter with the 5w-40 and it would start a bit easier.
Starting at 100K I switched my Jeep 4.0 to and from synthetic numerous times. It has a bit of a leak from the oil pan gasket, but nothing internal is leaking.
Starting at 100K I switched my Jeep 4.0 to and from synthetic numerous times. It has a bit of a leak from the oil pan gasket, but nothing internal is leaking.
It's been my experience that mechanics are not a good source of information about oil. They sometimes give advice that goes directly against the owner's manual and other times they have stories to support their claims that may have actually happened making their ability to learn something new an impossible task.
I take that one step further.... in general, mechanics are not a good source for anything except the football scores and who is the latest chick working at Hooters. On oil, coolant, grease, etc, they are about as lame as anyone else.
Originally Posted By: OneEyeJack
It's been my experience that mechanics are not a good source of information about oil. They sometimes give advice that goes directly against the owner's manual and other times they have stories to support their claims that may have actually happened making their ability to learn something new an impossible task.
A lot of "mechanics" that have gone to UTI, seem to think 20w-50 is the oil for everything ...
It's been my experience that mechanics are not a good source of information about oil. They sometimes give advice that goes directly against the owner's manual and other times they have stories to support their claims that may have actually happened making their ability to learn something new an impossible task.
A lot of "mechanics" that have gone to UTI, seem to think 20w-50 is the oil for everything ...
Originally Posted By: mrvmax
A respected diesel mechanic in the area claims switching to synthetic oil now will cause problems due to removing deposits and resulting in leaks and other issues and claims that he has seen this before.
Without wanting to contradict other advice you've received here, I think it was actually wise of the mechanic to give you this warning.
This isn't advice without context or knowledge ie it is not some passed along tale of the type frequently heard at Walmart. The mechanic is actually telling you a mechanism that is known to sometimes happened. Synthetic oils clean better and can remove false seals. If that happens, you then need to use an oil or an additive designed to stop leaks by swelling seals. The question is whether it is worth risking going through something like that.
This is a different problem to the earlier and since resolved problem with synthetics having seal incompatibilities.
Since your mechanic specifically referenced removal of deposits leading to leaks, he is referring to the false seals cleaned by synthetic issue which arises from using sub standard oils or over extending oil changes.
As has been mentioned, it is not necessarily the case that you have any false seals. It is going to depend on your engines preponderance to do something like that, the duty cycle of the vehicle, the quality of the oils used and whether the oil changes were actually performed as stated. If you are at all worried, then maybe evaluate this information as part of your decision making process.
The mechanic sees that your vehicle is 20 years old and has used conventional all the time so decides to warn you about switching. While the mechanism he outlined was realistic, he's not able to evaluate the risk of something happening to your vehicle beyond the two data points of a 20 year old vehicle that's always used conventional oil.
But from his position, and using the information at hand, it makes sense to be prudent. Why go all fancy pants with Amsoil and bypass filters when conventional is really just as capable and does not have any added risk? Plus if you use conventional, maybe he gets to service your vehicle more often.
A respected diesel mechanic in the area claims switching to synthetic oil now will cause problems due to removing deposits and resulting in leaks and other issues and claims that he has seen this before.
Without wanting to contradict other advice you've received here, I think it was actually wise of the mechanic to give you this warning.
This isn't advice without context or knowledge ie it is not some passed along tale of the type frequently heard at Walmart. The mechanic is actually telling you a mechanism that is known to sometimes happened. Synthetic oils clean better and can remove false seals. If that happens, you then need to use an oil or an additive designed to stop leaks by swelling seals. The question is whether it is worth risking going through something like that.
This is a different problem to the earlier and since resolved problem with synthetics having seal incompatibilities.
Since your mechanic specifically referenced removal of deposits leading to leaks, he is referring to the false seals cleaned by synthetic issue which arises from using sub standard oils or over extending oil changes.
As has been mentioned, it is not necessarily the case that you have any false seals. It is going to depend on your engines preponderance to do something like that, the duty cycle of the vehicle, the quality of the oils used and whether the oil changes were actually performed as stated. If you are at all worried, then maybe evaluate this information as part of your decision making process.
The mechanic sees that your vehicle is 20 years old and has used conventional all the time so decides to warn you about switching. While the mechanism he outlined was realistic, he's not able to evaluate the risk of something happening to your vehicle beyond the two data points of a 20 year old vehicle that's always used conventional oil.
But from his position, and using the information at hand, it makes sense to be prudent. Why go all fancy pants with Amsoil and bypass filters when conventional is really just as capable and does not have any added risk? Plus if you use conventional, maybe he gets to service your vehicle more often.
Originally Posted By: Miller88
Originally Posted By: OneEyeJack
It's been my experience that mechanics are not a good source of information about oil. They sometimes give advice that goes directly against the owner's manual and other times they have stories to support their claims that may have actually happened making their ability to learn something new an impossible task.
A lot of "mechanics" that have gone to UTI, seem to think 20w-50 is the oil for everything ...
That was a few years ago. 20w-50 has been replaced by 0w-40.
Originally Posted By: OneEyeJack
It's been my experience that mechanics are not a good source of information about oil. They sometimes give advice that goes directly against the owner's manual and other times they have stories to support their claims that may have actually happened making their ability to learn something new an impossible task.
A lot of "mechanics" that have gone to UTI, seem to think 20w-50 is the oil for everything ...
That was a few years ago. 20w-50 has been replaced by 0w-40.
Benito's advice is the one I've taken. I have two 15 year old cars unknown service history that I'm hesitant in using synthetic. Both cars don't leak oil now on conventional oil. If I use synthetic and a leak starts it might not stop if I switch back to conventional. Just seems like I could be opening up a can of worms. If you do a google search much pros and cons.
Both my new cars get synthetic from day one.
Both my new cars get synthetic from day one.
Going to a synthetic could be worth a shot. Do note, however, that an E7, E9 HDEO can also be conventional and can be a candidate for extended drains, too. The 1997 OCIs were ridiculously short, and to extend those, one doesn't automatically need bypass filtration and a synthetic. That certainly helps extend things much more, but there likely is more room for movement than you realize, as it is.
dnewton3
Staff member
Originally Posted By: Benito
... Synthetic oils clean better and can remove false seals. ...
Meeeehhhhhhh .... Not really.
That is certainly the preconceived notion out in public, but we here at BITOG ought to all know better. I'm going to take exception to this and define it in greater detail.
First, we have to accept that in this case, "syns" are referring to PAO, and not group III or V, just for the sake of this particular thread. I am limiting my comments as such in this context.
PAOs most certainly do resist oxidizing better than conventional stocks. I agree with that. So it might be fair to say that they "run cleaner". But I disagree that they "clean better". PAOs don't hold additives in suspension nearly as well as conventional base stocks; that is one of their limitations. Therefore they cannot "clean" better than a good quality dino HDEO with a robust additive package. Now, PAOs finished products have been modified to accept detergents in a meaningful way, but that does not give them an ability to "clean" any "better" than a dino with those same additives. Simply put, PAOs "run cleaner", but they don't necessarily "clean better". Therefore I find it a bit misleading to state that quote above.
Presuming this "new to him" 7.3L PSD was well cared for, and had regular OCIs, there's probably very little in the way of sludge/deposits on the seals, or anywhere else for that matter. Therefore you can't claim to be able to:
1) clean better when PAOs are limited in this regard contrasted to a robust dino
2) clean something that isn't likely there in the first place
I want to be clear that I am not a chemist, so I cannot explain all the intricate details of the elemental aspects of this topic. But after conversations with those who do fill that bill, this is probably a more accurate statement that the quote above.
Now, it was also true that older formulations of PAOs did react with some older seal materials, and actually cause the seals to shrink. But as I stated previously in this thread, those two topics have been addressed by the industry long ago. PAOs now have modified seal swellers, as I understand, as well as most automotive seals have been compatible for a long time now.
Therefore, we have to be careful when we talk about seal leaks in the first place.
Does the seal leak because of mechanical abrasion? (not the fault of any lube)
Does the seal leak because it hardened? (either chemical or heat induced)
Does the seal leak because of shrinking? (chemically induced)
It is possible, given the age of that '97 PDS, that some seals may be hardened by heat or old enough that material compatibility may be an issue. However, given that this PSD was claimed to be in good shape and had regular OCIs, plus he's using Amsoil, which is a very capable product line, and there's no leaks currently, I'd say he's OK to at least try it.
Part of the problem for this OP is that his trusted mechanic threw a blanket statement over a very detailed topic. And he is probably operating on old mentality when it comes to seal leaks using syns.
... Synthetic oils clean better and can remove false seals. ...
Meeeehhhhhhh .... Not really.
That is certainly the preconceived notion out in public, but we here at BITOG ought to all know better. I'm going to take exception to this and define it in greater detail.
First, we have to accept that in this case, "syns" are referring to PAO, and not group III or V, just for the sake of this particular thread. I am limiting my comments as such in this context.
PAOs most certainly do resist oxidizing better than conventional stocks. I agree with that. So it might be fair to say that they "run cleaner". But I disagree that they "clean better". PAOs don't hold additives in suspension nearly as well as conventional base stocks; that is one of their limitations. Therefore they cannot "clean" better than a good quality dino HDEO with a robust additive package. Now, PAOs finished products have been modified to accept detergents in a meaningful way, but that does not give them an ability to "clean" any "better" than a dino with those same additives. Simply put, PAOs "run cleaner", but they don't necessarily "clean better". Therefore I find it a bit misleading to state that quote above.
Presuming this "new to him" 7.3L PSD was well cared for, and had regular OCIs, there's probably very little in the way of sludge/deposits on the seals, or anywhere else for that matter. Therefore you can't claim to be able to:
1) clean better when PAOs are limited in this regard contrasted to a robust dino
2) clean something that isn't likely there in the first place
I want to be clear that I am not a chemist, so I cannot explain all the intricate details of the elemental aspects of this topic. But after conversations with those who do fill that bill, this is probably a more accurate statement that the quote above.
Now, it was also true that older formulations of PAOs did react with some older seal materials, and actually cause the seals to shrink. But as I stated previously in this thread, those two topics have been addressed by the industry long ago. PAOs now have modified seal swellers, as I understand, as well as most automotive seals have been compatible for a long time now.
Therefore, we have to be careful when we talk about seal leaks in the first place.
Does the seal leak because of mechanical abrasion? (not the fault of any lube)
Does the seal leak because it hardened? (either chemical or heat induced)
Does the seal leak because of shrinking? (chemically induced)
It is possible, given the age of that '97 PDS, that some seals may be hardened by heat or old enough that material compatibility may be an issue. However, given that this PSD was claimed to be in good shape and had regular OCIs, plus he's using Amsoil, which is a very capable product line, and there's no leaks currently, I'd say he's OK to at least try it.
Part of the problem for this OP is that his trusted mechanic threw a blanket statement over a very detailed topic. And he is probably operating on old mentality when it comes to seal leaks using syns.
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Ford oci is....
Severe: 3k / 200hrs
Normal: 5k
Engine is a member of the t444e IH family.
That being said, IH oci is....
Severe: 10k/ 6months / 350hrs
There engines have sumps in the 20+gets range.
I run dino usually and I run at 7,500miles and thing about changing.
I have no uoa's but feel I am dumping oil with plenty of life still.
Harvey
Severe: 3k / 200hrs
Normal: 5k
Engine is a member of the t444e IH family.
That being said, IH oci is....
Severe: 10k/ 6months / 350hrs
There engines have sumps in the 20+gets range.
I run dino usually and I run at 7,500miles and thing about changing.
I have no uoa's but feel I am dumping oil with plenty of life still.
Harvey
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dnewton3
Staff member
Originally Posted By: mrvmax
... I'm waiting for my Amsoil then I'll install the FS2500 and run it until the oil analysis tells me to change it.
Amsoil and FS2500 should make for some really long OCIs.
Color me skeptical; rare is the BITOGer who can keep his hands off the wrenches that long.
... I'm waiting for my Amsoil then I'll install the FS2500 and run it until the oil analysis tells me to change it.
Amsoil and FS2500 should make for some really long OCIs.
Color me skeptical; rare is the BITOGer who can keep his hands off the wrenches that long.
Originally Posted By: mrvmax
... A respected diesel mechanic in the area claims switching to synthetic oil now will cause problems due to removing deposits and resulting in leaks and other issues and claims that he has seen this before. I find it hard to believe but since he is an excellent diesel mechanic I want some advice....
Well, it seems as others have answered your question with their experience. Two other posts in here the users have noticed a slight leakage after switching.
So taking that into account, your respected mechanic is correct and you should continue to "respect" him! *L*
MILLIONS of vehicles on the road and two people out of 100 who maybe read it, in this forum reported a slight leakage, so you can bet your mechanic has seen SOME cases of this happening.
Does it mean it happens all the time? No but he does see the chance it could happen and you would not respect him, if he said, sure go ahead and switch to synthetic at your mileage only to find out you were one of the few who developed a leak.
)
... A respected diesel mechanic in the area claims switching to synthetic oil now will cause problems due to removing deposits and resulting in leaks and other issues and claims that he has seen this before. I find it hard to believe but since he is an excellent diesel mechanic I want some advice....
Well, it seems as others have answered your question with their experience. Two other posts in here the users have noticed a slight leakage after switching.
So taking that into account, your respected mechanic is correct and you should continue to "respect" him! *L*
MILLIONS of vehicles on the road and two people out of 100 who maybe read it, in this forum reported a slight leakage, so you can bet your mechanic has seen SOME cases of this happening.
Does it mean it happens all the time? No but he does see the chance it could happen and you would not respect him, if he said, sure go ahead and switch to synthetic at your mileage only to find out you were one of the few who developed a leak.
)
Speaking of mechanics making poor oil recommendations, one of our family members father in law owns a shop. Another family member had just bought a 99 Toyota 4Runner with the 3.4 v6 and the oil level was down towards the low level. I hadn't even checked the cap but assumed it was 5w30 (which it was) but he didn't look and said she needed 10w40 for this one. I even said I think they spec 5w30 but wouldn't hurt anything with 10w40. He just said no, they take a thicker oil than that. Poured a quart of 10w40 in there and I kept my mouth shut. You could plainly see the cap said 5w30 haha! Well, that cap was missing the rubber O ring so it was leaking. I bought her a cap at Autozone that doesn't say 5w30. Now they can pretend it's supposed to take 10w40 I guess.
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