Synthetic oil in high mileage engine

[mreloc]

Hi- new (old) 4runner owner here. 2002 SR5 with 114K miles.

I've read the posts about dangers of switching to synthetic in high mileage engines causing (uncovering) leaks. I have no idea how my truck was maintained except I found a dealer oil change sticker, so I'm presuming conventional oil changes over its life, not knowing how often they were done.

Am a synthetic guy at heart and really want to switch to Mobil 1, but want to hear others' experiences who may have made the switch at high mileage and what the results were (leaks? no leaks?)

Thanks!

 

[Koz]

Hi- new (old) 4runner owner here. 2002 SR5 with 114K miles.

I've read the posts about dangers of switching to synthetic in high mileage engines causing (uncovering) leaks. I have no idea how my truck was maintained except I found a dealer oil change sticker, so I'm presuming conventional oil changes over its life, not knowing how often they were done.

Am a synthetic guy at heart and really want to switch to Mobil 1, but want to hear others' experiences who may have made the switch at high mileage and what the results were (leaks? no leaks?)

Thanks!

Here's the problem; if only petro oil was used and the changes were stretched out beyond the recommended intervals, sludge could have coated the inside of the engine. The sludge could have coated the seals in the engine. When you start using synthetic oil (which has very aggressive detergents), the sludge that was sealing gaskets will now leak. Also the oil filter will collect the sludge and will need to be changed very frequently until the engine is clean.

This is not a guarantee but you can pull a valve cover to get an idea if there is sludge buildup.

If you do not know what type of oil was used and/or if it was changed at the recommended intervals I suggest you just use dino oil and just change it at the OEM recommended intervals. Trust me when I say; if you use synthetic and have these issues you WILL regret using it. It is not worth the troubles you will experience.

Koz

 

[mreloc]

Thanks for the balanced reply, Koz. Makes sense- I think I'll just proceed with Castrol dino 5w-30 and leave it at that. Altho the thought of the possibility of removing possible sludge does sound appealing

I will say this motor is whisper silent- timing belt and water pump were done 10k miles ago per the sticker on the cover. There is no hint of ticking or valve train noise at all, so I'm guessing the motor is in pretty good condition, overall. I think my first order of biz will be to put on an external transmission cooler that will eliminate milkshake risk... the thing that killed my Pilot with 55K miles on the clock.

 

[Supra725]

I used to ran Castrol through mine..

but now, I'm running Mobil 1 through it and I'm almost at 225k..

I have zero leaks after I changed from Castrol to Mobil..

how often do you change your oil?

 

[A/V1]

I used to ran Castrol through mine..

but now, I'm running Mobil 1 through it and I'm almost at 225k..

I have zero leaks after I changed from Castrol to Mobil.

:wow: 225k? Nice!

 

[mreloc]

I used to ran Castrol through mine..

but now, I'm running Mobil 1 through it and I'm almost at 225k..

I have zero leaks after I changed from Castrol to Mobil..

how often do you change your oil?

Good to know.. at what mileage did you change over? At 225K or sometime before that?

If I do dino, i would change every 3k, but synthetic I would go at least 5k.

 

[Supra725]

I believe around 180k I changed from Castrol to Mobil..

At Costco, sometimes they will mail a $10 dollars coupon off for 6 quarts of Mobil 1.

After the discount, is about $22 dollars for 6 quarts.. plus the filter $4 dollars..

especially in Winter where temperature drops below 0 degrees, is nice to know that your oil doesn't freeze like other oil does..

 

[mreloc]

I believe around 180k I changed from Castrol to Mobil..

At Costco, sometimes they will mail a $10 dollars coupon off for 6 quarts of Mobil 1.

After the discount, is about $22 dollars for 6 quarts.. plus the filter $4 dollars..

especially in Winter where temperature drops below 0 degrees, is nice to know that your oil doesn't freeze like other oil does..

Cool. So, did you have to replace your oil filter rather quickly since the Mobil1 probably cleaned whatever sludge was lurking in your engine?

 

[XJeepguy]

114K ? Barely broken in man IF your worried you could always send your dino in for a oil analysis to see what it says before switching . You have NO worries with that amount of mileage . Hell , I switched my Prelude at around 310K , no issues .

Hi- new (old) 4runner owner here. 2002 SR5 with 114K miles.

I've read the posts about dangers of switching to synthetic in high mileage engines causing (uncovering) leaks. I have no idea how my truck was maintained except I found a dealer oil change sticker, so I'm presuming conventional oil changes over its life, not knowing how often they were done.

Am a synthetic guy at heart and really want to switch to Mobil 1, but want to hear others' experiences who may have made the switch at high mileage and what the results were (leaks? no leaks?)

Thanks!

 

[Supra725]

nope.

I stuck with an oem toyota filter and I've been changing it around the 5k area..

 

[denverunner]

I started running M1 at 115k (currently sitting at 125k), and no "sludge-reduction" based leaks so far. I did have an incident where the o-ring on my filter didn't seat properly -causing a minor leak, but that was an oversight on my end.

I think, that if you "create" a leak by running full-syn, then thats something that will take a bit of time to develop. Like, a few or more oil changes. I don't htink you'll see something like that occur within the first full syn oil change.

(Granted, ymmv!)

 

[mreloc]

Thanks for the additional replies, guys. I think I've got enough confidence now to make the switch to M1

 

[Koz]

Thanks for the additional replies, guys. I think I've got enough confidence now to make the switch to M1

I would suggest pulling a valve cover to see if there is any sludge build-up before switching.

Koz

 

[mreloc]

I would suggest pulling a valve cover to see if there is any sludge build-up before switching.

Koz

Good suggestion. Anyone know what the torque specs of the valve cover bolts are off hand?

 

[T4RBoarder]

Switched 4 trucks over to M1 at 100k plus and not a single problem yet

 

[blaniac22]

I had a similar concern - though my 4R only has 36K miles on it. Now that the free dealer oil changes have run their course I was going to switch over to M1 Synthetic.

Your question prompted me to do a little research and I found this:

Switching to Synthetic Oil in Higher Mileage Vehicles


Does switching from a petroleum-based oil to a fully synthetic oil on a higher mileage vehicle (75,000 miles) have any harmful effects? I've heard that the synthetic oil, because it is cleaner, may actually loosen some of the build-up from petroleum oil and has the potential of clogging the pump. Is this true or does one simply need to change the filter more frequently for the first few thousand miles after switching? Thanks
-- Michael Ritzke, Appleton, WI

Answer:
When switching to Mobil 1 in higher mileage vehicles, we recommend an initial short (2,000 to 3,000 miles) oil change, both oil and filter. This will allow Mobil 1 to clean some of the engine deposits that have accumulated over time. Following this initial short oil change, continue with your normal oil change interval.

 

[Koz]

Again, if you do not know if the oil (Dino) was changed regularly there could be sludge build up in the engine. If there is sludge, it could be a VERY involved and lengthy procedure to remove it. There are good engine flush products that will remove the sludge but there is also the risk of leaks. If there is sludge I recommend to leave it be and use dino oil and just change it as per OEM recommendation.

Koz

 

[Koz]

Answer:
When switching to Mobil 1 in higher mileage vehicles, we recommend an initial short (2,000 to 3,000 miles) oil change, both oil and filter. This will allow Mobil 1 to clean some of the engine deposits that have accumulated over time. Following this initial short oil change, continue with your normal oil change interval.[/I][/B]

First off one oil change is not going to be enough to clear the sludge and why would you use expensive synthetic oil and dump it at 2-3K miles. That is rediculous. If you want to remove sludge you would use a product like Auto RX and use the cheapest oil you can find to dump at 1-2K miles. It may take three or more changes (W/filter) to clear the sludge. At this point keep your fingers crossed that there are no leaks. If there are, there is not much you can do!

Koz

 

[XJeepguy]

IMO , I think that's overkill dude . Get your M1 and OEM filter and just do it .

Good suggestion. Anyone know what the torque specs of the valve cover bolts are off hand?

 

[blaniac22]

First off one oil change is not going to be enough to clear the sludge and why would you use expensive synthetic oil and dump it at 2-3K miles. That is rediculous. If you want to remove sludge you would use a product like Auto RX and use the cheapest oil you can find to dump at 1-2K miles. It may take three or more changes (W/filter) to clear the sludge. At this point keep your fingers crossed that there are no leaks. If there are, there is not much you can do!

Koz

Koz - I'm not questioning your knowledge. After reading through a lot of posts over the years I know you are one of the "go to" guys on the site.

I just wanted to put what Mobil 1 says about it - granted they have something to gain and want to sell their oil. And as others have said, I'm sure many have done it on high mileage engines without any problems. It really boils down to risk/reward and if the person is willing to take the risk.

Not to Hijack the thread - what is the latest you would consider switching? Is 36K to late?