Opinions on using full synthetic oil in a high milage engine Topic is solved

[ashitaka695]

I have a 1994 850 NA with 300,000 on the clock. It's my first Volvo I have owned or even worked on. I've been using the forum quite a bit and it has helped me a lot. I've heard various opinions about my Volvo, good and bad but either way I love hearing what people have to say. I have always used synthetic oil specifically Shell Rotella T6 in every vehicle I've owned. I've never had a vehicle with milage as high as this that runs as well as this Volvo does. It doesn't leak or burn any oil but has the crankcase breather problem. I plan on replacing the breather soon with a complete kit but for now I keep the dipstick raised a bit when I take a drive. It's not driven often maybe once or twice a week. It's a project that has no intended purpose just a fun weekend toy. I've done one oil change and used Rotella T6. I want to hear opinions about synthetic oils. What kind do you guys use or prefer? Or if you don't use synthetic oil, why? And with high milage such as mine, recommendations on oils whether synthetic or conventional and the reasons why you would choose that oil.

[abscate]

I moved all my cars to synthetic to lengthen my oil change intervals and reduce chance of sludging my two turbos.

I had no issues of leaks or burning or seeping , if anything all three were reduced compared to Dino oil.

Volvos 7500 mile changes
Beetle 5000 mile changes ( 24 months)
Eurovan 5000 mile changes (24 months)
I've been changing these annually but after dropping the pan and sludge inspecting I'm going to 2 year intervals on these. These are both lightly driven cars.

BMW 12500-15000 changes. The BMW forum says I've destroyed my engine doing this. It's got 140k on it.

[shiloh51933]

Ever since buying my first Volvo (1996 850GLT w/Platinum model rims) I've been hooked. That 96 had 300,000 b4 a burnt exhaust valve and not fixing something caused the burnt valve. Then I bought my wife a '04 XC70 Xenon headlights model and myself a '98 v70xc. My '98 served its purpose but had many issues when I purchased, far too many to keep up with. I lost the 98' when it hydro locked due major coolant leak during use and level sensor light never went off, the temp needle never went up either but I had a/c running so fans stayed on possible keeping it cool enough until she was totally dry. I bought another Volvo, a 2000 V70XCse and she is as close to mint as I could find. Suspension is gd, motor is good after replacing air charge tube and heater core hoses. I love my new V70XCse and my wife loves her 04 XC70!!
I always change over to synthetic as long as the motor is solid without leaks, full synthetic leaks quickly and you wallet will leak quickly buying all that synthetic oil. I use Liqui Moly Leichtlauf 5w40 with Mann filters in our 04' XC70 and I used Mobil 1 in our '96, the 98 had a leak so synthetic blended Cam2. The 2000 is going to get Liqui Moly, oil was changed b4 purchase so I'll do it shortly.

[rspi]

I would NOT recommend it until you service the PCV.

[polskamafia mjl]

I recommend using synthetic. I'm giving the Shell Rotella T6 a try right now in my T5R with 281K miles. Usually I run Mobile 1 10w40 or 5W40.

[sleddriver]

I ran Rotella T6 20W-50 for several years. Hard to beat the price. 10,000 change with a filter change every 5000 mi. No worries. Remember, where I live we only have two seasons: Summer & February. Currently running M1 10W-30HM. Car burns no oil.

Turbo motors & synthetic are indeed a match made in heaven! No PCV clogging, no sludge, no coked turbo.

[ashitaka695]

I think my Volvo was last owned by a young kid or someone who didn't know how to work on vehicles. The fuel pump was wired with a speaker wire to a hot in position 2 on the ignition switch so if you wanted to listen to the radio the pump came on. I rewired it back to original and found that the relay needed to be replaced. After that I still had low fuel pressure. I pulled the pump and the line from the pump to the top of the tank wasn't clamped tight at all. After this repair it ran great. That's when I decided that it was going to be my new project. It's been surprise after surprise for me many good, some bad. The biggest is the milage and the fact that it has no leaks or oil burning. Since the oil change no leaks have developed and the little bit of blow-by through the dipstick hasn't even changed the oil level yet 1200 miles into the oil change. The breather repairs are on hold until I can get a few other things done to it. The friend that sold the car to me has pretty much any used parts imaginable and I've already got quite a few parts from him. I want to buy a few things new such as suspension parts, motor mounts and brakes (I have put new used pads for now but I want to do a complete brake job) I feel that as long as no major engine repairs are needed it's worth it to build it back to original condition. I'm going to try for 500,000 miles do you guys think it's a possibility?

[scot850]

Not if you don't do the PCV/breather service. If you do the glove test over the oil filler and it inflates, you have crankcase pressure that will blow out a seal, and possibly the rear main seal at worst. Before suspension, mounts (unless broken) and brakes (unless faulty/worn out) this should be your first job.

Neil.

[Sommerfeldt]

Neil's right - the PCV is one of the most important things to get out of the way. It's a good system when it's working, and a killer when it's not.

I recently changed to Mobil1 0W40 synth, btw - it's been working great, and got rid of a little ticking under load.

- S

[zhenya]

I have never had any negative effects from switching any older car to synthetic. In fact in both of my p80 Volvo's I've seen only benefits - greatly reduced oil consumption in the 850 and in the V70 it eliminated a few pesky leaks I had.