Thump like sound, yes I've searched and nothing
- Thread starter Nitesaber
- Start date
riotwarrior
Full Access Member
Best edumacated guess...at least 1 valve...the huff comes amd goes as the valve finds sweet spot to seal and then moves....likely ....harmonics of a running engine are much different than a free spin comp test and why it doesnt show in comp test always...
A leakdown test may lead you where you need to go .....but 150 rpm comp test is slow and eazy for valve to seat vs 900 rpm and the pressures generated etc.
Look for bent pushrods too or bad valve springs....heads being new likely not alot of soot discharge yet.
Mine was chuff out exhaust ...others have had similar issues too.
http://www.oilburners.net/forums/sh...alve-breaks-POST-MORTEM&highlight=Post+mortem
Hope you find issue prior to catastrphic failure......not like me....a post mortem
A leakdown test may lead you where you need to go .....but 150 rpm comp test is slow and eazy for valve to seat vs 900 rpm and the pressures generated etc.
Look for bent pushrods too or bad valve springs....heads being new likely not alot of soot discharge yet.
Mine was chuff out exhaust ...others have had similar issues too.
http://www.oilburners.net/forums/sh...alve-breaks-POST-MORTEM&highlight=Post+mortem
Hope you find issue prior to catastrphic failure......not like me....a post mortem
I have my eyes on a motor as of now, worse case I completely swap motors. Best case is I'm just swapping heads if this is a valve issue. Motor has 110k miles all original. All New injectors, pump, and lines, a new alt, new belt, new water pump, etc. he's asking $1500, sound reasonable?
Hydro-idi
Full Access Member
I would rather fix what you got and do the job properly. I would take both cylinder heads off, send them to a reputable machine shop and have them check heads thoroughly.
Spending $1500 for a used engine that's in questionable condition is not what I would do. And no, that is not a good deal by any means IMO.
Spending $1500 for a used engine that's in questionable condition is not what I would do. And no, that is not a good deal by any means IMO.
hesutton
The Anti-Anderson
That is commonly suggested. However, I have tried this personally looking for which injectors are bad or good. I've never had this technique help me chase down a bad injector, and I've had my share over the years. Recently had a stuck injector on my F250. Very similar symptoms to what you are having. But, several things can give these symptoms. Biggest clue for me was the fuel leak at the return cap, very hot injection line and injector, and the injector itself was not at torque spec anymore (ate the cooper washer completely). Pulled the injection line off and saw soot at the top of the injector. Fired up the truck with the line off and compression was coming out of the top of the injector. Cap was melted.
Heath
icanfixall
Official GMM hand model
Well Heath that injector sure was a leaking thru...
To the original poster. Please warm up the engine and then feel each injector line near the injector but be careful. If an injector is failing that injector hard line might be blistering hot. What happened to Heath is an injector failed to shut off completely after pulsing fuel into the cylinder. So the 450 to 550 lbs of hot compression is driven back into the injector line where it melts the plastic return line cap. I recall you mentioned you replaced the injectors with new. Please tell us where you purchased them and were the new rebuilts or new remanufactured... Ebay has some shady sellers getting unsuspecting buyers believing they are buying new injectors when they are really buying cleaned up old injector mascrading as new. NEVER buy a "new" painted injector or injection pump. Painting covers up the dirt and makes something look new.. Its like the saying.. Its a rattle can rebuild.... Thats when a seller paints something and "claims" its been rebuilt.
Black dawg
Registered User
From listening to this video, I am not so sure of my original thoughts on this. sounds more like fuel related knock.
Didnt see any diagnosing in that video.....just staring?
Where does the noise sound like it is coming from (stethoscope??)
why not take it back to this shop that did all this work recently?
No point just driving it till it possibly grenades.
I have to drive it, no work no money. If it fails I can use a work truck but until then boss won't budge on me using one. With that being said the idle has become extremely rough. No longer smooth but lots of vibration through the cab. I felt the lines but nothing searing hot. Gentlemen I know said to check the washer holding the injector to the block as it may be bad or not torqued enough and is causing a huge loss in compression.
mblaney
Full Access Member
Well a quick check is to pull all of the injectors and check for soot, and then pop test. That might be better than circling the truck and not doing anything. It will be obvious if you have a copper seal problem or loose injector. You you don't have a pop tester you can build one pretty easy and you will have it for life. You can search here for homemade pop tester.
If you pull your injectors make sure you have new o-rings. I suggest getting a bag of Viton size 111 from any good hydraulics shop or McMaster Carr. Start to finish you can have your injectors all popped in an hour or two and then move on.
If you pull your injectors make sure you have new o-rings. I suggest getting a bag of Viton size 111 from any good hydraulics shop or McMaster Carr. Start to finish you can have your injectors all popped in an hour or two and then move on.
icanfixall
Official GMM hand model
An easy way to test this idea is spray some soapy water on the injector at the head. If ANY bubbles show up you have a bad copper gasket or a bad seat under the gasket. Might try tightening the loose injector if you find one also. You still have not told us what and where you got the injectors. I'm knid of wondering why you have not commented on this yet???
This forum will not shame you for a mistake purchasing a less that best part for this engine. for the most part we all search for "good deals" when we can. Sadly many of the good deals on parts turn into the worst deal because we end up paying the price by buying the part twice.
An easy way to test this idea is spray some soapy water on the injector at the head. If ANY bubbles show up you have a bad copper gasket or a bad seat under the gasket. Might try tightening the loose injector if you find one also. You still have not told us what and where you got the injectors. I'm knid of wondering why you have not commented on this yet???
This forum will not shame you for a mistake purchasing a less that best part for this engine. for the most part we all search for "good deals" when we can. Sadly many of the good deals on parts turn into the worst deal because we end up paying the price by buying the part twice.
I never put new injectors on this truck. I was looking at a truck with new injectors and pump and lines. I have been in contact with R&D about injectors and possible head. He is getting pricing on head now and injectors are on back order waiting on new nozzles to come in. Ill pull the injectors and check for soot and Ill look up pop tester
onebadiditurbo
Full Access Member
This is a stab in the dark and I'll agree it does sound like a valve issue, but how are your brakes? If you depress pedal and again right after is pedal hard? Reason I ask is i chased a similar noise for a bit and assumed the worse come to find out I had a bad vacuum pump!
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