Smoking rebuilt Perkins Diesel help needed!!!

[Rasselas36]

It is your injectors. Get them cleaned or worse rebuilt.

[dancor01]

Originally Posted by Sojourner

t Initially it spat some oil, but probably this was leftover due to a leaky old turbo which was replaced with new. On startup a few days ago (cold start, not run in a few weeks) it spat diesel enough to slick the water a good 5 meters all around the boat (see pic), never before and not again. But it never stopped smoking like this. Where should I start looking???

Here are the facts: 1991 Perkins. Rebuilt and rebored, this was the first rebuild. Everything looked good. Injectors checked out good. New turbo installed. Ran about 20 hours, 14 of which were under 2/3 load in the water, the rest idling at the marina. No change in smoke based on temps outside or in engine, or hours run (six hour under load run, still the same). Engine temps normal (80 C). Engine sounds fine, no vibration or off-beat rhythm. Just the smoke.

Few keywords in what was said.
Spat oil on startup after rebuilt. Normal for few seconds. The reason. When you rebuilt an engine you apply oil on the rings, cylinder and piston to make sure they don't run dry on the first startup.


Second keyword re-bored..... That is a big one.
When you re-bore a cylinder Bigger piston/rings are needed. The second question where the rings installed properly. You just don't put them on like that.


White smoke???? To much fuel or not enough air. Also could be from a leaking head gasket. Head wasn't torqued properly.


There are mechanics, and parts changer. Unfortunately. the real mechanics are getting harder to find each days

[Juggerknot]

I use dinosaur oil during break in of a fresh rebuild, using synthetic lube can inhibit proper ring seating. Once broken in I switch to synthetic... I agree with a pump timing check and having your injectors pop tested and adjust accordingly will make for a nice smooth running diesel. Good lu k

[Juggerknot]

Originally Posted by Sojourner

Update: So I talked to a trusted owner friend who has lived here for a long time with 3 big boats, ie he has a good mechanic, whom he asked to come over straight away. Dude came over and looked at it, stethoscoped it with a dowel, checked for contamination in oil/radiator/under caps etc... He thinks it's gonna be a top end issue, valves or valve seals. Wants to pull the top off and take it to some pro rebuilder. Seems adamant it is not unburnt diesel.

Should I force him to start with less invasive things like pulling/testing injectors and compression before ripping into the motor? I dont think it is a timing issue cause the engine is reassembled and set back exactly at the marks. But still smells like unburnt diesel to me.

Do blown valve seals produce both unburnt diesel and oil? Seems like they could....

Bad seals meaning seats or guides? Either way you will have big blow by...easy to check, fire it up and open oil filler cap, is it dancing around with obvious oil vapor and crankcase gasses spewing from the cap that is resting on the valve cover? If not the the valvetrain is tight. Conversely you can check your rings and crankcase pressure by examining the volume of gasses exiting your dipstick tube. These are merely shadetree mechanic's tricks however useful in preliminary diagnosis. Leakdown and compression tests will give you a clearer picture without pulling a head. Keep us posted plz

[pendragon]

After a rebuilt:
The solution to stop the spitting of dirty fuel oil out of the exhaust, is to change the current lub oil to what is called "running-in oil for diesels."
This type of oil beds in the rings fast, thus preventing spitting and giving more compression, thus more efficiency.
After around 50 hours running, change oil back to the recommended, as per your manual.

[RUSTYNAIL]

I remember pulling into Mazatlan in my father's Islander Freeport 36 wth a Perkins engine. We came from Puerto Vallarta. There was lots of smoke and the transom was black. A mechanic came out, took the air filter to his shop, cleaned the little holes, brought it back, and no more smoke all the way to San Diego.

[Sojourner]

UPDATE: The engine was pulled. The top end inspected and torn down and put back together by a shop everyone tells me is the best around. The block was pulled out and inspected, and they found the gaps in the cylinder rings were perfectly aligned on several cylinders.... which they believe was the cause of burning oil. Seems logical enough. I heard several tales that the rings will migrate under use, but perhaps at the same rate, so by not aligning them at 120 degrees to each other at the outset, that might explain why it always blew smoke hot or cold, but a little less when hot. They're reassembling it with OEM cylinder head gaskets and we'll see what we see in a few days.....wish me luck!

So far I'm not paying for any of this so at least I got that going for me....

[Kenomac]

I'm sorry to hear about your engine issue. Regarding your video, next time it's easier to post the video on youtube then, paste the youtube address for your video on your post.

[moesgaard61.tm]

Originally Posted by Sojourner

My freshly rebuilt Perkins Prima T80 turbo is smoking and spitting diesel, and I need some help please. i know I'm always the one asking stupid questions and being annoying, but the guys are telling me this is either "normal" or "dunno" or "it'll stop eventually" and I'm getting a bit fed up. I've worked on engines before, tho never diesels...it can't be normal to smoke worse than the 50 year old fishing tubs going past my bow every morning... It cost a lot of money I don't have and I'm not leaving without a properly done engine. Please, any diesel mavens out there chime in and let me know where / how to start diagnosing this....

Ever since the rebuild, the engine has been smoking no more and no less than what's in the video. Initially it spat some oil, but probably this was leftover due to a leaky old turbo which was replaced with new. On startup a few days ago (cold start, not run in a few weeks) it spat diesel enough to slick the water a good 5 meters all around the boat (see pic), never before and not again. But it never stopped smoking like this. Where should I start looking???

Here are the facts: 1991 Perkins. Rebuilt and rebored, this was the first rebuild. Everything looked good. Injectors checked out good. New turbo installed. Ran about 20 hours, 14 of which were under 2/3 load in the water, the rest idling at the marina. No change in smoke based on temps outside or in engine, or hours run (six hour under load run, still the same). Engine temps normal (80 C). Engine sounds fine, no vibration or off-beat rhythm. Just the smoke.

Anyone, I would very much appreciate some tips on where to get started.... Thanks so much!

Hi

I think you may try to check the valve stem guides and the oil `thiefs` because White smoke i from lube oil.

/Thomas

[catman]

Hide the cigarettes.
A little humour never hurts.
Cheers

[Sojourner]

Ciao y'all! Thought I'd let you know what happened with that smokey engine of mine...

Remember I said I couldn't tell if the smoke was white or blue? That's cause it was BOTH

1) Three of the four cylinders had been reassembled with the correct/specified 120 degree offset of the rings. The fourth? They lined up exactly like someone used a ruler. Turned them properly and the oil sheen and blue smoke went away.

BUT there was still plenty of white smoke and diesel sheen! So...

2) The 3 year old injectors were cleaned and tested when originally rebuilt, so they were eliminated from suspicion early on. However, it turned out that they were set/made to offer fuel at 175 atm pressure.... the PO missed that. My engine wants 225atm injectors. I think over the years and hours (6000 when he replaced the originals with the 175s) meant the compression was already lower, and so it wasn't noticed as smoking very much back then. A bit, which is why I overhauled, but not terrible. With the over-bored pistons, brand new everything, I think the deficiency really came out. I found the original Perkins injectors onboard (which, being an amazing PO, he had had cleaned, adjusted, and packed away in the spare parts of the boat when I bought it). Had them tested again to be sure (yup, 225 on the nose) and installed them. Poof! Or rather lack thereof.... white smoke gone.

Thanks all you guys for the advice and support as always! With the engine fixed and everything else refitted, it's time for a quick visit from my dad and then we're off to greece to start filming again and just in general living our damn lives not tied to a dock.....cannnnnot wait

[NYSail]

Congrats on the success! Enjoy......

[Sojourner]

Originally Posted by Cherp

I assume when you say the engine was rebuilt/refurbished, that the head got a decent working over as well. Otherwise you will have good compression from a rebuilt lower end finding the weaknesses in the old head.

Yup, I did. New turbo as well (that was the first thing to start sucking after the rebuild for a similar reason). Just never actually tested the release pressure of the damn injectors!

[RUSTYNAIL]

That was very kind of you to explain in detail, the fix. I'll tuck this away in my old brain and it may save me a lot of time in the future, for my 4.236.

[oldtom]

Originally Posted by Sojourner

Ciao y'all! Thought I'd let you know what happened with that smokey engine of mine...

Remember I said I couldn't tell if the smoke was white or blue? That's cause it was BOTH

1) Three of the four cylinders had been reassembled with the correct/specified 120 degree offset of the rings. The fourth? They lined up exactly like someone used a ruler. Turned them properly and the oil sheen and blue smoke went away.

BUT there was still plenty of white smoke and diesel sheen! So...

2) The 3 year old injectors were cleaned and tested when originally rebuilt, so they were eliminated from suspicion early on. However, it turned out that they were set/made to offer fuel at 175 atm pressure.... the PO missed that. My engine wants 225atm injectors. I think over the years and hours (6000 when he replaced the originals with the 175s) meant the compression was already lower, and so it wasn't noticed as smoking very much back then. A bit, which is why I overhauled, but not terrible. With the over-bored pistons, brand new everything, I think the deficiency really came out. I found the original Perkins injectors onboard (which, being an amazing PO, he had had cleaned, adjusted, and packed away in the spare parts of the boat when I bought it). Had them tested again to be sure (yup, 225 on the nose) and installed them. Poof! Or rather lack thereof.... white smoke gone.

Thanks all you guys for the advice and support as always! With the engine fixed and everything else refitted, it's time for a quick visit from my dad and then we're off to greece to start filming again and just in general living our damn lives not tied to a dock.....cannnnnot wait

Pump gov,timing r.p.m settings are on plate on fuel pumps or you look up OME codes same for crackpressure for injectors so fuel system was set up incorrectly,as for piston ring gap spacing would have come up with compression test