Blow by on a rebuild???

[TDsamurai]

Ok so i had my 1.6TD rebuilt at a local shop that i have done business with before and heard good things about. I had this done 17, 000km ago.

I immediately had some issues around crankcase ventilation and oil consumption. I understand that with chromoly piston rings can take quite some time for the rings to seat and there will be some oil consumption during the break in period.

So my question is how much oil was your engine consuming after a full rebuild? not just a re ring, my engine was bored .20 over with new pistons and the whole deal.

At about 2000km i still had oil consumption issues so i decided to do some investigating. I popped of the crankcase breather from the intake and ran it to a temporary catch can. After 50km of driving my engine pumped out 250ml of oil. I mentioned this to the engine builder and they told me it could do this for up to 6000km during break in. In response they told me chromoly rings are a pain to seat so drive it like i stole it. Personally i think that much oil is excessive. What do you think?

Now heres the big problem. My engine after 17,000km would only run on 3 cylinders. So i yanked it out and brought it back to the shop.

Cylinders were streaked, rings frozen to pistons and some rings broken. They shop has determined that the combustion temperatures were too hot. Now being that i have an EGT gauge and i carefully monitor this i find that hard to believe. Now yes my EGT is not my combustion temperature however i would expect it to be directly proportional to the combustion temp as the heat generally does come out the exhaust.

So far it has not been decided who will be paying for the damage or how much it will cost.

My theory is either some machining error or ring assembly error causing my initial excessive blowby which as a result was adding fuel (crankcase vapour) into the intake which could easily contribute to excessive combustion temperatures. As you may know this is very difficult to prove on both my part and the builders part.

As for details of my engine. It was fully rebuilt, top and bottom end. The injection pump rebuilt, and new injectors. Running 25psi of boost with ARP studs and MLS gasket. 2.5" straight exhaust. And a small top mount intercooler. I thought i had covered all the bases, but after i get my engine back i will also be running water meth injection and an after market oil cooler.

For break in procedure i tried to work the engine up steep hills and drive it hard however being careful not to over rev or "lug" it. I have heard break in is very critical, however i have also heard it is quite difficult to screw up a break in as long as the engine is working not idleing and what not.

So anyway im sure you can imagine my frustration, let me know what you think. Obviously i am not thrilled on paying for new pistons, the machining, and all the labour. Im not one to point fingers but it seems that is what the engine shop is doing to me.

When i mentioned the oil in the intake being the cause of temperatures, their response is that the rings weren't seated so there will be blow by. But a cup of oil in 50km seems a bit much.

I look forward to your input thanks for the help in advance guys.

[Thezorn]

I recently rebuilt my 1.9TD. Since the rebuild I have put, so far, 4200km roughly and have only added about 1 liter of oil since then. From that 1 liter, probabley 3/4s was actually lost from leaks and a very marginall amount burned.
If the shop told you to drive it like you stole it I personally wouldnt trust them. From what Ive been told, and just a personall common sence view on the matter, you are supposed to do the exact opposite. I drove mine very, very mildly for the first 2-300km or so maybe up to 2k rpms max, then began to drive it as I would normall before I built the engine, staying out of the boost as much as possible of course. I waited till about 1500 to 2000km till I started to really get into the boost (Its also compound turbo'd, so you can imagine how hard that was)

There is alot of things they could have done to mess this up, Installe dthe rings with the gaps all lined up, hit the pistons into the cylinders with a hammer or some type of mallet and cracked or broke the rings.

I did the rebuild on my car myslef, just had the machine shop clean everything, deck the block and head, hot tank and polish the crank and re-cross hatch the cylinders so if anything goes wrong Im the only one to blame. If I was in your shoes I would personally point the finger at the shop for the faulty workmanship by the sounds of it.

I would also check out all the bearings if I was you just to be sure, who knows what could be happening if your pistons look like they do. Try and get some pics or the carnage if possible. Check your oil filter and see if it has any metal shavings in it, if there is lots check your oil pump and strainer to maybe?

Not sure if this really helps but it was my personal experience and also personal views from when I rebuilt my engine, It was also the first engine I every built
 

[theman53]

I think you did ok. I would say the shop is crazy for putting in chromoly rings. Those take forever in a gas engine and they take a different hone, so that maybe the problem.
As for break in I think differently then the zorn. I didn't drive mine like I stole it, but I did cycle the engine slowly through the RPM band. Keeping it under redline, but taking my time getting it there and making it work the whole time. I did baby it for the first 100 miles at low RPM, then went to keeping it under redline. I did this as my first gasser used oil when I broke it in keeping it low RPM until a few thousand miles. Everytime I got on it and really into the higher RPM range it would use oil, but if I kept it under 3,000RPM it wouldn't use a drop. An old guy told me to break it in differently*like I have above* and I wouldn't have had that problem.
My current build uses maybe 2oz in 5,000 miles. It used to leak/burn about 16oz in 3,000 miles, but now that all the leaks are fixed I really don't use it. I think the first 300 miles I used 8oz, but there were leaks in there too. After that it all slowed down to nill.
I would find out what brand of ring and piston they used. If it was the Prothe pistons they are usually good but his rings suck and do what you have said happened to you. I would get the Goetze rings for you pistons if they are still in spec for your engine. Make sure you have the .001" bore spec and you should be good.

[TDsamurai]

The bearings appear to be OK, and there was no metal in the oil filter. Why would you say they are crazy for using chrome rings? isnt that factory for these engines? im not so sure cast rings will support my 25psi of boost. I guess i will be more gentle with the engine when i get it this time. I new i had too much blow by from the start. Ive spent 10 000 at this machine shop in the last 3 years and i have sent lots of business there, i hope they take care of me.

[rodpaslow]

my .02 - I use a provent filter now on mine.  I don't have a connection to the lower part of the block.  I've tried a couple times to connect a vent line to the lower block plate (just below and to the right of the inj. pump.  Both times I tried it I get large amount of oil coming out of there.   Like you said about 250 mls or more with just a 15 in drive.  I don't know if this is only my engine or not. other people do it and have no problem, with mine I can't.  I have a large 1" connection to the valve cover vent going to my provent filter back into the engine.  I have maybe 15000 miles on my engine and uses maybe 1 liter between oil changes.  (my engine is a 92 1.6td usually running a max of about 20 psi.)

[TDsamurai]

This test was before i upgraded my oil seperator to the later style that drains to the block, after the upgrade it did cut back a bit, still i was going through about 3 litres between oil changes and i was doing oil changes after 3000km. After the rebuild i think i did an oil change after 500km and then another in 1000km and another 1000km and then every 3000km.

[R.O.R-2.0]

have you been running it up thru the entire RPM range?

you really need to beat on these diesels a bit to seat the rings good.. well, not really beat on them, but definitely rev them a bit. keep them under a load (driving the car)

my rings on the 1.5TD i built took FOREVER to seat. had blow by for about 10k miles with normal rings..

moly rings have a really hard face, and it takes even longer to seat them..

[TDsamurai]

Well they told me to beat on it so yea i was driving it pretty hard. And definately was using the revs. What kind of oil consumption did you have early on in the break in?

[theman53]

I don't know what the factory used but all the rings I have were iron. If I were to do it again I would buy the Goetze and send them to total seal.

[R.O.R-2.0]

Well they told me to beat on it so yea i was driving it pretty hard. And definately was using the revs. What kind of oil consumption did you have early on in the break in?

i used over a quart in the first 500 miles, then changed it, and used another quart in 3000 miles.. then it slowed down after that.

[R.O.R-2.0]

I don't know what the factory used but all the rings I have were iron. If I were to do it again I would buy the Goetze and send them to total seal.

send them to total seal? to have them build rings for our engines? they dont already make something that fits?

[TDsamurai]

Ok i just heard from the machine shop the cylinder head is not useable, the block needs to be re bored and i need new pistons+rings. And they still think a cup of oil in 50km out the breather is normal... We will see what they want to charge me for.

[R.O.R-2.0]

Ok i just heard from the machine shop the cylinder head is not useable, the block needs to be re bored and i need new pistons+rings. And they still think a cup of oil in 50km out the breather is normal... We will see what they want to charge me for.

sounds like the shop did some $#!tty work on your engine..

no, its not normal for a cup of oil to come out the breather in 50 km..

the amount of oil out the breather should be almost un-measurable..

[DJPyro]

....K wait, so what happened to the head? I don't see why it would be unusable now unless it was unusable before, although it's been a long day so I might've missed something.

I'm using Goetze rings, and burned/leaked quite a bit of oil for the first 2000km or so, ever since then, the only oil I lose is from the known leaks I haven't addressed yet.

Also, I am of the same mind as theman53, I went fairly easy on my car for the first couple hundred Km or so, to make sure everything was doing ok, then I just did as much varied driving as possible, racked up a few thousand km of up and down in the RPM band, and every type of load I could put on it, from decel down a nice long hill, to a good high boost run back up it. You have to consider that your rings seal based partially on combustion chamber pressures, so you can't go too easy on it or it won't push the rings hard enough into the cylinder wall to seat them properly. I've got a friend with a 1000whp+ turbo 300zx, he built his motor and then broke it in on 20psi and hard dyno pulls. He hasn't had an issue since. The first few hours of runtime on a motor are key for getting the rings to seat nicely, as that's when your crosshatch is the roughest and will allow the rings and cylinder walls to match themselves nicely. Also, consider doing the rebuild yourself, if you have the space and tools to swap it into a Sami, you have the knowledge and most of the tools you'll need to rebuild it. It's fairly easy with a manual and some basic mechanical aptitude.


Coles: I second using Goetze rings, and I'm more of a believer in the "hard break-in" school.

[R.O.R-2.0]

....K wait, so what happened to the head? I don't see why it would be unusable now unless it was unusable before, although it's been a long day so I might've missed something.

I'm using Goetze rings, and burned/leaked quite a bit of oil for the first 2000km or so, ever since then, the only oil I lose is from the known leaks I haven't addressed yet.

Also, I am of the same mind as theman53, I went fairly easy on my car for the first couple hundred Km or so, to make sure everything was doing ok, then I just did as much varied driving as possible, racked up a few thousand km of up and down in the RPM band, and every type of load I could put on it, from decel down a nice long hill, to a good high boost run back up it. You have to consider that your rings seal based partially on combustion chamber pressures, so you can't go too easy on it or it won't push the rings hard enough into the cylinder wall to seat them properly. I've got a friend with a 1000whp+ turbo 300zx, he built his motor and then broke it in on 20psi and hard dyno pulls. He hasn't had an issue since. The first few hours of runtime on a motor are key for getting the rings to seat nicely, as that's when your crosshatch is the roughest and will allow the rings and cylinder walls to match themselves nicely. Also, consider doing the rebuild yourself, if you have the space and tools to swap it into a Sami, you have the knowledge and most of the tools you'll need to rebuild it. It's fairly easy with a manual and some basic mechanical aptitude.


Coles: I second using Goetze rings, and I'm more of a believer in the "hard break-in" school.

i dont get the way of thinking by some people..

build an engine, break it in on oh, 3 psi boost, then once its broken in, crank it up to 30 psi.. i mean, come on.. WTF? seriously?

the engines i build, i break them in exactly as they are going to be driven..

i also believe in the "run it like ya stole it" break in method.