I think I'm going back to conventional oil.

[wtd]

I've decided to switch back to conventional oil for awhile in my 98 chevy Z71 with the 5.7L. I've been doing oil analysis on this truck for a little over two years and have yet to get a really good report using the Mobil 1. It seems like I see plenty of good reports using conventional oils and most of them have been better than mine running a synthetic. Most of the comments from Blackstone Labs recommends changing my oil every 3-4,000 miles using the Mobil 1 so I just can't justify spending that kind of money on an oil that isn't performing well in my engine. Since I also have a small coolant leak inside the engine, I have to change the oil every 3,000 miles anyway.

I just changed the oil yesterday at 2,561 miles and sent it to Blackstone to see if the coolant leak is getting worse. This was 10W-30 Mobil 1. I put in 5W-30 Havoline conventional oil with Lube Control and will do an analysis of this oil after 3,000 miles. I picked up a case of 5W-30 Chevron Supreme from the local distributor and will run this after the Havoline.

The engine is much quieter with the Havoline than it was with the Mobil 1. The engine was ticking pretty loud before I changed the oil. I'm curious to see how my wear numbers will compare to the Mobil 1.

Wayne

 

[JohnBrowning]

Fix the truck first then go back to synthetics!! No oil can make up for mechanical issues!

 

[W.T.McGlynn]

Try some "Barrs Leak" to stop the Coolent leak.
GM does before it leaves the Factory.
Good Luck !

 

[williar]

Like the others said, get the coolant issue taken care of then...

Unless you're willing to leave the M1 in for 7500 miles, I'd go back to dino, too. Change it out every 3000-5000 miles and your engine wlll be happy.

 

[Flimflam]

quote:

---

Originally posted by wtd:
I've been doing oil analysis...... and have yet to get a really good report using the Mobil 1. It seems like I see plenty of good reports using conventional oils.........

Wayne

---

That is the point I've been trying to make for donks (donkey's years). People seem to want to change over to Synthetic Oil just to follow the crowd. They never ask themselves, "Now, for $5 a quart instead of 99 cents a quart, will my Car really be doing better?" One High-profile Oil Company says in its Ad's, "With our oil, cars go over 200,000 miles." Well guess what? My buddy who services 1/2 the airport limousine fleets in a major city (Lincoln Continentals exclusively) has never seen a car go less than 250,000 miles; Notwithstanding Acts of God, like a hunk of Twin Towers falling out of the sky and flattening a new Lincoln.

And it is a pretty cunning PR Campaign, too, because these days, few people keep their cars for 80,000 miles, let alone 200,000 miles. So, the average Joe will never know if the claims of Big Oil are true.

But thefact is, these days, almost any car will go 200,000 miles, regardless of the type or brand of oil used, provided the oil has all the nesessary current ratings: API, ILSAC, etc.

 

[wtd]

To address the question about mechanical issues, the ticking noise has been present for many years and was addressed when the truck was new and under warrenty. It started at around 14,000 when I first switched to Mobil 1. It is now my belief that Mobil 1 might be too thin for my engine. The dealer and various other shops have said that nothing is wrong and that some of these engines are louder than others. I've not yet had anyplace offer to take my money and try and fix this. There have been many posts here and on other forums where vehicles running a synthetic, have been noisier than ones running a conventional oil.

As far as the coolant leak goes, my oil analysis results were not great way before I had this coolant leak and it only showed up on my last analysis. I had four previous analysis's done.

Time will tell if I made the right decision but I've been having doubts about running synthetics for awhile now. Thinking back on my last truck (93 S-10 4x4 bought new) which I used synthetics in (Castrol Syntec & Mobil 1), I remember that by the time I got rid of it at 54,000 miles, the engine (4.3L V-6) was very noisy and it was using oil. I took excellent care of this truck as it was my first new vehicle and it got oil changes every 3 months or 3,000 miles even with synthetic. I change the oil on a friend of mines 2000 chevy truck with the 4.3L V-6 using Mobil 1 5W-30 and his engine is noisy. I've been changing oil on this truck since it was new and its had nothing but Mobil 1 in it. It might all just be coincidence, I don't know. I'm not saying synthetics are bad, but they just might not be right for my particular engine. I can always switch back if my results are worse than they are now.

Is there anyone here that went from synthetics to dino oil and got better analysis results?

Wayne

 

[buster]

quote:

---

Fix the truck first then go back to synthetics!! No oil can make up for mechanical issues!

---

Exactly. Certain oils hide the problem better but it has nothing to do with the oil.

 

[JohnBrowning]

WTD, UOA is to an engine what blood tests are to our bodies. If you get a bad blood test you do not dumb your blood. You fix what is wrong. Acelerated wear is an indicator that you have problems in this engine besides the coolant leak. The coolant leak is just makeing these issues more seveer!

You said it yourself. You have never had a good UOA and the truck was giveing you problems as early on as 14,000 miles.

I suspect that when you tear this engine down and blue print it you will find your problem.

 

[Robbie Alexander]

Although I donno what Blueprint is, I agree with John here about finding the problem / s.

quote:

---

Originally posted by wtd:
I've decided to switch back to conventional oil for awhile -----******
--> If you want, but you may or may not be changing more often. Example: The problems I have
been having with SI and wear metals in my oil, when I did not have the problems, I was getting over 30K sometimes 16-20K without changing but maybe 1 filter maybe 2; after the problem it got worse and worse, going to 24K max, then say 10-12 ish then perhaps 8, then say like 6, and lastly like 2.5K which was the worst... the thing is when you have a problem it gets worse, if you know the source, fix the problem, then worry about oil later, right now your car is in the Ambulance, You Do not want it to pull into the Hospital not stable... so if you have a problem breathing put on an oxygen mask and fix the problem before the car goes into shock.


It seems like I see plenty of good reports using conventional oils ------*****
------> sure, and it may be more cost beneficial to you, it is in my application. But you need to cange the oil more often until you get this thing fixed.
*******

The engine is much quieter with the Havoline than it was with the Mobil 1. -*-*-*-*-*

---

Quiet does not have anything to do with it. In some cases yes, but with this leak and any other problem you have with wear, anything to make it quiet does not mean the problem is at bay...

 

[Patman]

Wayne, you might want to try one of the high mileage oils to see if the thicker viscosity does help your wear numbers come down or not.

 

[wtd]

Well, some of you guys might be right about a mechanical problem but tearing the engine down is not an option at this point. I just don't have that kind of money right now. The startup knock problem with this truck is a common one that affects these engines after awhile. I've heard plenty of them do it and according to the dealer and many other shops that I've talked to, it won't affect durability. They may be full of it, but that is what I've been told.

Right now I can't hear any startup knock but it may be because the oil is new and will come back as the oil gets older. I always get less startup knock running a 5W-30 than with the 10W-30.

Thanks for all of the input.

Wayne

 

[csandste]

We have some delivery vans from the mid-eighties that have 250,000 miles on them. Engines still working strong, but the rest of the vehicles are pure crap. I've said it enough to be sickening, but it does little to extend the life of an engine way beyond the life of the rest of the vehicle. Before I tore the engine down over a leak, I too would throw some Bars leak into it.

Curious as to the switch between Havoline and Chevron-- better price or a feeling that the Chevron add. pack is better?

 

[Bror Jace]

“ … the ticking noise has been present for many years and was addressed when the truck was new and under warranty. It started at around 14,000 when I first switched to Mobil 1.”

This is common with Mobil 1, especially in cold weather. My Honda Civic got so bad one winter my dad (a Ford driver

) was laughing at me and said that my “POS furrin’ car was about to throw a rod.” Well, I switched oils some time after that (both other synthetics & synthetic blends) and the noise all but disappeared. I put another 50,000+ miles on the car before selling it to a neighbor who’ll be driving it for years to come, I’m sure.

I have no idea why it occurs, but I’ve lost track of owners complaining about engine noise when using Mobil 1. Not just the older Tri-Syn but the newer SuperSyn as well.

Wayne, I think I told you about 2 years ago that you’d probably be better off with conventional oil and more frequent changes. I’m not surprised your engine has quieted down since your switch. I for one think you are on the right track with this recent switch.

Pennzoil or Chevron Supreme conventional oils … especially in 10W30 would probably be your best bet. However, either brand 5W30 should be shear stable enough for 3,000-4,000 mile oil & filter drains. Patman beat me to it but I also think one of the higher mileage oils may be just the thing. Pennzoil High Mileage Vehicle oils is available in a 5W30 … but it is significantly thicker than regular 5W30s and I might not want to use it in the winter. Come spring or summer it would be interesting if the ester additives in this oil have any effect on analysis.

Having said all that, I’m not sure the fault lies with the synthetic oils. I really think GM’s quality control has worsened … especially with these old (nearly ancient) design motors which, if assembled well, would go 300,000 miles without a major failure using an unremarkable maintenance schedule and cheap oil & filters. If they just sort of slap them together, most will make it to the 100,000 mile mark with a few going well beyond that point. GM just doesn’t seem interested in making them any better than they have to. And, you’re hearing this from a guy who was a diehard Chevy man 15+ years ago.

“…is the coolant leak bad enough that you have to add coolant periodically? If you are not losing coolant, I wouldn't worry about it.”

I can’t agree with that, JTK. Even trace amounts of coolant in the oil can double or even triple wear in the bearings. So, short drain intervals are a must until you get it resolved. In my case, I drove around with a suspected leak for about a year before I was confident enough to take it to a shop … and when they popped the head off, they found the leak in the head gasket.

If Wayne doesn’t want to knock the motor apart right now, he’s gonna have to decrease his interval, watch his temp gauge & coolant level AND probably send samples for periodic UOAs. Once this problem becomes more obvious (perhaps isolate it to one bank of cylinders), then consider taking it to a shop for either more testing (leak-down) or replacement work.

Wayne, not to put the fear or God in you, but you might want to keep your eye open for a used 350 motor. If you can get one with low miles and/or mildly rebuilt, it might be worth dropping it into your truck if it comes to that a few years from now. Nothing urgent but if you keep your ear to the ground, you may be able to find something cheap which may let you get a handful more years out of your truck … assuming the body, etc … is holding up well.

--- Bror Jace

 

[wtd]

csandste,
The reason I am going to switch from Havoline to Chevron is because I've seen lots of good oil analysis's with this oil and hardly any from Havoline. I know its been said that they pretty much have the same specs but who knows. No one around here sells the chevron in the stores so I found a local distributor and bought a case of it.

JTK,
I am losing some coolant from the overflow tank but not alot yet. Like I said before, there are no signs of coolant in the oil or under the PCV valve. The dye that was put in my coolant is not showing up in the oil either. I'm going to be watching my oil pretty often and changing it every 3,000 miles. I'm also using Lube Control which should help protect the engine.

Bror Jace,
I'm going to stick with a 5W-30 oil for the winter and will probably go with 10W-30 for the summer. I'm going to try Chevron Supreme and see how it works in my truck.

I'm not blameing synthetics for any of my problems but when my oil analysis's come back with the comments to stay with 3 or 4,000 miles oil changes using the Mobil 1, then I'm just throwing my money away. I cannot justify spending that kind of money when I'm not seeing better results.

The truck is in excellent condition, inside and out, so if the motor goes in a few years, I'll just get a GM crate motor and put it in.

For anyone,
Since the dealer cannot pinpoint where the coolant is going at this time and the fact that I have limited funds at the moment, what would you do if this was your truck? Keep an eye on things or have someone start tearing this motor apart. Dealer quote on just the intake manifold repair is $400 and removing the heads will probably be double that. Thanks for all of the input.

Wayne

 

[userfriendly]

The only "true synthetic" that is mass marketed is Mobil-1. Is there that many complaints using their product??
Does M-1 cause engines to be noisy?
I've never heard of anyone complaining about group III synthetics causing engine problems.
I guess it is because in actual field use they are superior to PAOs???

Has anyone tested head to head POAs, conventionals, and group IIIs?
If that were my truck I'd use a group III 5W40 in the winter, and either an SAE 30, 40, or 15W40 the rest of the year.
A high 30s, such as a 10W30 HDMO that has a vis of 11.5-12.2 would be a good three season engine oil.
Save the synthetics for winter unless you find a good group III 5W40 cheap. Like $2.00/qt Havoline I saw mentioned in another thread.
Try a new rad cap with a little less pressure, and a 180* thermostate.

 

[JTK]

Wayne, is the coolant leak bad enough that you have to add coolant periodically? If you are not loosing coolant, I wouldn't worry about it. Stick with the dino & fix it when you start loosing coolant or have performace issues.
G/luck
Joel

 

[mikep]

wtd....based on what you said, I too would probably take a wait and see attitude. The crate motor thing is always an option down the road. You'll easily blow a thousand dollars at a dealership having this problem corrected and from what I've seen at most dealerships, there's a good chance they won't truly fix the problem at all.

I completely agree that using M1 in this situation is a huge waste of money. Chevron Supereme, Citgo Superguard, GTX...any of the proven Dinos will do well at a 3-4 thousand mile drain...especially if you're using LC. Whichever you choose to go with I would absolutely have a UOA done at 3,000 miles and see what the lab says.

Userfriendly,

regarding M1 and complaints about it making engines noisy.....I'll raise my hand. Last winter, while trying to find an oil that may lessen the xtreme cold, first morning start tapping/slap (whatever you want to call it) I tried some M1. I can't recall if it was 5w-30 or 0w-30 but I think it was 0w-30. Anyway, the noise at startup with M1 in the pan was the absolute loudest I'd ever heard. It was like fingernails on a blackboard and I drained it after only a week or two. Not saying M1 would do that for any engine but it sure did for my 4.6 ltr v8 on cold winter morning startups.

Mikep

 

[Ray H]

quote:

---

Originally posted by wtd:
The reason I am going to switch from Havoline to Chevron is because I've seen lots of good oil analysis's with this oil and hardly any from Havoline. I know its been said that they pretty much have the same specs but who knows.

---

ChevronTexaco knows and you can read the specs yourself for both "brands" if you're willing to navigate ChevronTexaco's arcane website. Or you can just continue to assume they're different formulas.

 

[MarkC]

I spoke with the Chevron tech rep, an also read the spec sheets. Havoline and Chevron oils are the same, with the exception that Havoline adds a little magnesium , while Chevron uses calcium only.

 

[mikep]

quote:

---

Originally posted by MarkC:
I spoke with the Chevron tech rep, an also read the spec sheets. Havoline and Chevron oils are the same, with the exception that Havoline adds a little magnesium , while Chevron uses calcium only.

---

So the Havoline has the Isosyn additive?

Mikep