engine break in period

[redcanoe]

Have just had new pistons and cylinders installed. What is the opinion out there on the "warm up" time prior to driving during the break in period. I'm on Vancouver Is. in BC for climate information purposes.

1. Let the vehicle idle a couple of minutes and then go. Taking it easy once rolling.

2. Let the vehicle idle until up to normal operating temperature and then go.

Understand that I should be using regular motor oil during the initial break in period after that changing to synthetic. I mistakenly had synthetic installed right away (less than 150 kms) and now hear that I should drain that and install regular 10/40 for the break in and then back to the synthetic.

What do you think?

[82WestyMan]

First off, you should mention what engine you have since there's more than few for vanagons...

Second, the synthetic oil is suppose to be bad news for a new motor because it won't let the rings seat properly and 150 km is a long time to have driven it... that's about covers the break-in period for rings

There is some discussion that this isn't the case with newer cars since they are built to closer tolerances... but a vanagon isn't a newer car and i doubt replacement parts qualify

From what I've heard and read, about the only way to properly break-in the rings now is...

Pull the pistons and cylinders, replace the rings and have the cylinders rehoned

It has to do with how the new rings seat (wear into) the new cylinder walls

There are many discussions about it when you do a google search on "break-in synthetic oil car"
_________________
"The floggings will continue until morale improves"
"I never did give anybody hell. I just told the truth and they thought it was hell" - Harry S. Truman
82 Westfalia - w/ a Raby 'Camper Special' engine

[morymob]

Does the eng smoke-oil smoke? If not all may not be lost, need to go on a drive where you can speed up an down,do this for several miles,dont go past 50mph & dont rev it hi,needs to be done in 4th gear if possible. Cool down,check oil level and do again,then with eng warm do compression check,if in specs and even,no smoke u r probably ok.. if ok at this point drive it easy for next 500mi,if still ok i would change oil at this point. Rings need to be loaded to seat,as in fairly short pulls and slow down as above,as for synthetics im not sold yet at the prices & imhave gone 300k+ on just major brand oils without any problems,my 2cts.

[funagon]

Don't tear down your engine, not yet. You can probably just switch to regular oil and drive easy (don't bother with the extended idling warmup) for the recommended period until the rings are seated.

Having said that, I have a real preference for the break-in method advocated by morymob. If you do an internet search you should find lots of info about putting load on the engine (both accelerating and decelerating) to seat the rings quickly and thoroughly. Our own tencentlife has written on this forum about this traditional break in method and a search might turn up his informative post.

I'm not an expert car guy so I don't speak from extensive experience, but here's my personal experience: for the past 4-5 years I've been working on my own cars including building engines. I broke in a stock WBX with new stock Mahle pistons/rings/jugs, and also broke in a set of new Gowesty 2.2 pistons, with the methods advocated by Mr. Tencent. I quickly got good compression and my engine doesn't burn or lose any oil, so I'm sold. I suspect that gearheads and mechanics know this is a good method for break in, but auto manufacturers know they can't depend upon millions of new car buyers to go out and faithfully apply careful break-in instructions, hence the common advice to "drive easy" for the first thousand miles.

Here's the post I was thinking of:

http://www.thesamba.com/vw/forum/viewtopic.php?t=201670&highlight=breakin+engine

[Wildthings]

Personally I would just start it up and drive it relatively hard with minimum time under no load or at idle. I honestly don't know if running synthetic on a newly rebuilt WBX engine would have any bad affects or not, but if I had to guess I would say its just another old mechanic's take.