Greetings,
Just curious, I have heard different versions on what is normal in the first 500 miles of a rebuilt engine. With 75 miles on my new short block, I have some smoke (more so at idle only). I have been told to be patient and wait until the "rings seal properly" and the oil burning will stop. Can anyone confirm this theory?

My head was rebuilt with new seals 2 years ago, but I suppose if the engine does not stop smoking in the 500 or 1K miles, maybe I should entertain the fact that a valve seal is bunk.

Any input?
Thanks in advance.

 

Hey there, are you sure the smoke you see is oil? Have you noticed the oil on the dipstick getting low? Are the valves adjusted properly .008 .0012? You said it was a new short block, so tapered cylinder walls should have been machined/ honed out. It's not uncommon for a little smoke to blow by while the rings seat in the first stages of break in.

 

Yeah I am sure it is oil (blue smoke). With only 75 miles on the new engine, only a little oil has shown to be used.

I will double check the valve adjustements again...Pretty sure they should be correct.

 

I wouldn't worry about it until the mileage gets a tad higher. You are using dinosaur juice right? Stuff doesn't seat properly with synthetic. I really doubt it's a bad valve seal because they (usually) don't let enough oil by to make easily visible smoke, unless multiple valve seals are leaking very badly. If you have detected any oil loss at all after only 75 miles, it's probably getting by the rings. Follow the rebuilder's recommendations for break-in and that should do just fine, and also preserve any applicable warranty if you ever need it!

 

The performance shop that rebuilt my short block recommended SAE 30 for the first 500 miles then 15w 40 or 20w50. Also pure distilled water in coolant system for first 500 miles so coolant doesn't 'slip' past the new gaskets. In summer don't worry about over heating per water cools better than 50-50, the antifreeze is more for it name...antifreeze.
HTH
Nathan

 

Follow up-

Well with now 280 miles on it, there is still no sign of the smoking letting up. Puff by puff my hair is falling out. For some darn reason, I really have a gut feeling it is not a "break-in period" issue. I have noticed minimal oil usage. I would "hope" that if it was breaking in, I would see a little decrease in smoke by now.

I am using natural oil (Crisco ) actually 10w30 and it has been changed once.

I should also note that the engine did smoke like this before the short block rebuild. The valve clearances have been checked and are exact.

Now for the kicker, another club member had his engine done (full long block) at exact same time I had mine done at the same shop. He reports no smoking from his...... :cry:

 

Ruh roh! I was really hoping your first thought was wrong However, you may be right... did you have the head done along with the rebuild? Does kinda sound like a bad valve/s:pat: You did check the valvelash... Have you pulled a plug to look for oil fouling? I would check all four. That might give you an indication of wher it's getting by. And maybe a leakdown test is in order in another 200 miles or so. Sorry for your frustration man... maybe a then look at it again.

 

I had the head re-done about 2 years ago so I "ass-umed" all was well with it, hence the reason I only did a short block rebuilt at this time.

Thanks for the input, I have pulled the plugs and noticed a little fouling (what I beleive to be fouling at least) on a couple of them.

I will replace the valve seals now and give it a whirl. Im going to try this method of replacing them with the head on the engine (filling the cylinder with air).

Ok, I think i'm ready....

 

Despite a pounding migraine, I think I found the problem. This is on the exhaust side, it appears that the replacement valve seals done two years ago were either installed wrong, or were the wrong seals.

What do you think?

 

Yuppers, I would say that could be it! What a PIA that is. Got the new seals yet???:pat:

 

Yes, it was not a pretty sight in the garage this morning.... One would say I was a tad frusterated. Oh well, such is life I suppose. At least I found the problem.

As far as the seals go, ya know, the Haynes manual I have specifically mentions that there are intake and exhaust specific seals. In the Fel-Pro engine gasket kit I purchased, they give me eight valve seals. I'll be darned if I see a difference in any of them. ????

 

FEL-PRO... you need not say more I used a fel pro head gasket on my old 22re, within a month it was bunk. Swapped it out with a TOYOTA and wha la! Problem solved. Looks like you had to peel the head off, may as well get the "good stuff". At least you know things will be better soon!

 

Yes, the "air in the cylinder" didnt work out well for me. Within 5 mins I started to hear bubbling in the radiator. Maybe it was that Fel Pro HG giving way I have used FP before with no issues, but at this point your right. I have lost enough hair, better go with OEM gaskets...

 

Just a final follow up- The beast is running excellent now and no smoke! Huray! It appears as the machine shop that worked on my head some years ago may not have known what they were doing. After the new shop went through the head, they discovered all types of issues. Nevertheless, wow what a difference now. Dare I say it is almost "fast"....(for a 4 cyl pushing 35's)

Anyway, thanks to all for the input.

BTW, if anyone is in need of a great machine shop, Pro Machine (SLC, Utah) is simply put, excellent! David Yates (owner) is one great person and is very meticulous in his work! Great rates as well (for exam: 22RE rebuilt shortblock $575 with core).

Take care.