Need help on switching high mileage diesel engine to synthetic

[The Critic]

Long post

My friend has a 1980 VW Pickup which had a diesel engine in it. Back in 1998, the engine died and he had a brand new diesel engine installed. This new diesel engine that he has installed was originally made I think for an early '90s Jetta.
Since then, the engine has been used for over 150,000 miles, but less than 180,000 miles. The oil has been changed every 3,000 miles with Chevron Delo 400 15w40. This truck is used for a 60 mile daily commute to work; the driving style for this truck is probably 80% highway/ 20% city.
Recently, he became interested in using synthetic oil in this engine. I suggested that he do a clean and rinse cycle of Auto-RX. He bought one bottle of Auto-RX, this engine has a 4.5 quart sump capacity; and will add it to his engine oil once he receives it. The oil was only changed 1,000 miles ago, so he'll just add it to the existing oil and install a new oil filter. By the way, is the right way to do it? After doing the cleaning phase for 1500 miles, he'll change the oil/filter and do a 2,000-3,000 mile run with Chevron Delo 400 15w40.
Since this person will probably do 6,000-9,000 mile drains with synthetic oil, I suggested that he go with Shell Rotella T 5W-40 synthetic oil. I think in my opinion that this oil offers the best price to performance ratio at around $12-$13/gallon.
Please tell me if I'm doing this "right." By using Auto-Rx the way that I'm planning to, am I going to get the most out of the product? If you have a better way, please feel free to make any suggestions. I'm open to suggestions. By the way, this truck has recently started reading high oil pressure. If you happen to know the causes of high oil pressure, please feel free to suggest a way to deal with the problem; would the Auto-Rx help? Finally, I think that Rotella T 5W-40 Synthetic is the best oil for his driving style and drain intervals; its price to performance ratio is hard to beat. Please correct me if I'm wrong, and if you think there is a better synthetic oil out there that will work better for his driving style and drain intervals, please feel free to make suggestions.

Michael

 

[Bio-T]

Your plan for the Auto-Rx clean is solid. I would do two cleans for high mileage over 100K miles though.

I had 2 VW Rabbits, both 1979. I was in cold weather at the time. 30 days of temps below 0. I had to run 10% gasoline mixed with #1 diesel to get the blame thing to start. That winter of mixing gas cost me a new injector pump, but it ran every day. Work was a priority at that time.

 

[TexasTDI]

Personally, I would have just used a bottle of Berryman's B-12 or Amsoil Engine flush to clean the dino oil crud out of the engine before switching to synthetic. Just pour the bottle in your oil when the engine is cold, start the engine, let it run for about 15 minutes, and drain the oil.

But your plan sounds good, too.

 

[The Critic]

Thanks everyone for their advice. I think then that I'll go ahead and carry out my Auto-RX plan. By the way, please provide me with some suggestions on which synthetic oil to use. Finally, if you happen to have the knowledge, what can cause high oil pressure, would the Auto-Rx help?

Michael

 

[TexasTDI]

quote:

---

Originally posted by Michael Wan:
By the way, please provide me with some suggestions on which synthetic oil to use.

---

Amsoil 15w40

 

[Rat407]

How high is the oil pressure. Right now on my brand new rebuild with all new bearings, pistons, and rings I have low oil pressure. What exactly is the oil pressure reading? Did he hook up a known good mechanical gage? Where is the reading taken, from the head or down at the oil filter? Depends on the engines year of build whether it has mechanical lifters or hydraulic. The mechanical lifter engines have higher oil pressure from what i have read on another forum. Make sure he uses a good quality oil filter, a Mahle, Mann, Bosch are all good filters for this application. Other filters have been known to blow apart. It is not uncommon for the oil pressure at winter cold start up to peg out 100 psi. The Auto-Rx will work well. It made a difference on my 91 Jetta TD. It really seemed to free up the turbo, at least it seems to spool faster when cold.

 

[The Critic]

Rat,
The oil pressure is taken from an onboard gauge, which is “sensing” from an unknown location. However, this is no question as to whether the oil pressure is high, since the oil filter did “bloat” consistently upon startup. The temporary solution: Idle the engine for about 10 minutes, and the oil pressure will drop back down to normal. A waste of fuel plus unneeded fuel dilution in the oil, but it solved the problem temporarily.

Update:
The truck finally finished two Auto-RX clean/rinse cycles with Delo 400 as of yesterday. The oil pressure was reading between 120-140psi prior to the Auto-RX clean and rinse cycles, but the Auto-RX did lower the oil pressure to between 100-120 psi (cleaning out sludge???). The oil pressure problem was resolved mid-way toward the 2nd Auto-RX cleaning cycle, and it indeed turned out to be a bad oil pressure relief within the oil pump, at the same time, the high oil pressure had destroyed the oil pan and valve cover gaskets, which were both replaced at the time as well. The mechanic noted that the valve cover appeared “very clean.” In addition, a leaky oil pressure sending unit was discovered and was also replaced.

We've had some trouble finding quality filters for this truck. Unfortunately, Fram seems to be the only aftermarket filter that we've been able to find. The owner checked the Supertech line and found that they did not make a suitable filter, and even stopped yesterday to see if Purolator had a suitable filter since the Premium Plus filters were onsale for $1.50, no luck. Therefore, the truck is currently using a Fram Extra Guard Filter.

Yesterday, the truck was taken into Wally's Lube Express and Rotella T Synthetic 5w-40 was installed along with a new Fram Extra Guard oil filter for a 5K OCI. Cost: $35

I think the owner will stay at the 5K OCI for now. So far, no leaks, and no consumption quite yet; will keep you folks updated.

As for now, Auto-RX lived up to its promise!

Michael

 

[Ken2]

Mail order a bunch of Mann or Mahle filters for that engine. Or German Bosch.

Check www.foreigncarpartsonline.com or any on-line seller. You might be able to find the filters in a local import shop at a good price.

Doesn't your local NAPA auto parts store have their very good NAPA-Gold filters for that engine?


Ken

 

[Steve S]

Why switch???

 

[Robert R. Wilson]

Those VW Diesel engines were famous for problems with the pressure relieve valve sticking. A friend of mine had so many filters blow off the engine that he carried filters and oil in the car at all times.

Bob

 

[deepsquat]

see now Micheal this is the type of vehicheal and driving style that i see no problem at all with a 10000 mile oil change interval ..diesel 60 mile one way commute very easy on the oil ..plus you cleaned the engine out with ARX first ..perfect!

 

[The Critic]

Thanks everyone for your advice, I'll look into using the Mann Filters.

TS has told me that the older VWs use the same filters as the newer Audi/VW cars, if that's really the case, I'll check into that.

Wilson, the mechanic who fixed the oil pressure relief valve stated that the valve was "completely broken," and had to replace the oil pump since they were one unit. The problem as yet to return, the oil pressure is back to normal.

How long should the owner go before dumping this fill? I was thinking 5-6K, perhaps longer with analysis. However, 5-6K IMO is a comfortable interval if they decide not to have their oil analyzed.

So far, its been 500 miles, still no consumption or leaks. The truck was taken up to an area with colder weather 40-50F, and experienced MUCH easier starting compared to Delo.

Time will tell.

Michael

 

[Vstrom]

quote:

---

Originally posted by Michael Wan:
the high oil pressure had destroyed the oil pan and valve cover gaskets, which were both replaced at the time as well.

---

Huh? Very unusual for either of those to be under ANY oil pressure. Is the VW engine that "different" or was this a SWAG?

 

[Hubjeep]

quote:

---

Originally posted by TexasTDI:
...Berryman's B-12...

---

Is SeaFoam similar to Berryman's B-12?

I want to throw something in the Benz 602 engine (125,000 miles) before switching from Dino to Delvac-1.

Also, should I change the filter after 1,000 miles or so after switching (I read this was a good idea).

I plan to run the Delvac-1 for about 7,500 miles.

Thanks,
John