VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: brownni on January 16, 2014, 06:04:26 pm
-
I recently got my 1981 1.6 NA caddy up and running really nicely by swapping out an old injection pump with a fresh reman from thedieselstore.com. During the swap I took my injectors to a local diesel shop and had them checked. They said the injectors were working fine - good spray pattern and popping within 2 bar of each other. I set the timing at 0.95mm and it starts fine, and runs pretty nicely when it is warmed up. However, I have been noticing some intermittent misses - or maybe extra clatter is a better description. It is pretty random, and seems most common at high loads and lower rpms/higher rpms. It is very quiet and even sounding at cruise in the mid rpm range.
The only strange thing I see is that there are large air bubbles in the apexes of the return lines - could that be the cause of my issue? Is it possible that there are some bad injectors? Does my description sound like pre-ignition? The sound is very similar to the pinging that I had in a 91 toyota 4runner gasser engine that was worn out. If it is pre-ignition, is that bad?
I really just want this thing running well - I have yet to find a great diesel mechanic around Utah that knows mk1's very well, or IDI's for that matter (brother has a ford IDI) and I really just want some peace of mind that these noises either need to be remedied or are acceptable.
-
Seeing air in the returns is normal.
I'd back the timing off to .90 and see how it goes.
-
Thanks - I will give that a try and report back.
-
I retarded the timing back to 0.90mm.
Result after about 100 miles of driving is that the popping/pinging is less frequent than before, and less loud, however, it is still there. I am not sure how to proceed as I know it is an abnormal sound, but once the engine is warm the power delivery is very smooth and it has what I consider to be very good power.
The most unusual thing about the engine aside from this intermittent pre-ignition (what I have decided to call it) is that at cold start-up (temps in the low 20s F ) it has quite a bit of white/blueish smoke for two or three minutes and then that clears right up and I am left with just the intermittent noises as described earlier.
Is there any chance that the injectors can stick intermittently?
The sound is a lot like the sound of the truck at idle when the timing is way to far advanced - which is why I suspect that.
-
Try a little less timing, ie 0.85 to 0.88 or a little more fuel.
-
Are you sure your timing everywhere is correct and your valves, etc. are good?
Can you really trust this shop?
Are you sure you aren't getting air intrusion at pump inlet? What about when stabbing the throttle?
I have seen many crazy things happen with injectors. Sticking, nailing, smoking, etc. Funny I was able to drive my cars through all of these engines, but if you daily drive them like me you learn to pick up on normal noises.
It gets into the teens here and I time all my cars just a tick below high end spec in bently. I use idle and advance lever before turning the cars over which do so within a second or two of cranking. Engines cackle but run smooth. I also don't get the steady white diesel smoke beyond the initial puff and less than 10 second of running. Never had so much as a stumble pounding any of my cars, unless of course a fuel filter is clogged :)
I like to start with each good runner I come across by breaking down pumps to clean and reseal. And get a workover on injectors from a reputable place.
I have freed up sticky injectors before temporarily by running straight atf through fuel filter on car for a couple minutes then letting car sit for a day, and then doing it again. I rescued a car once that was left to sit a couple days with a bad wvo/gas blend that caked everything up so much the car wouldn't start. Got it driving, even though later I pulled pump apart and there was buildup on moving parts still.
-
I'm not convinced you have a problem....quite frankly.
Can you post a video with good sound qualities?
-
I daily drive this truck and that's why I am trying to get it just right. I ran it with a bad injection pump (timing didn't advance) for about a year before finally getting a new one. The only other VW diesel I have driven is my wife's 2012 JSW TDi, which doesn't give me a great point of reference for normal sounds for a 1981 idi diesel. So I can't say I know what is or isn't normal sounds.
I am pretty sure (~ 99%) that the rest of the engine is timed properly - the camshaft/crankshaft timing is dead on. Also, I am sure that I am measuring the timing of the pump correctly as well. Also, I have checked and double checked the valve clearances and they all look in spec too.
I retarded back to 0.85mm and aside from being a little tougher to start, it still sounds about the same. The truck fires almost immediately when dead cold after the glowplug light turns off but it doesn't run in a manner I would call "smooth" until I just drive for a minute or two - by the time it is idling smoothly, the white smoke is gone.
I am attaching a link to a video of the truck running. I drove around the block just prior to taking this video so although the engine isn't totally warm, it didn't need glow plugs to start, nor did it have any smoke.
https://drive.google.com/file/d/0ByfxKCNwCdupUFJmcUYtMmVWVkU/edit?usp=sharing (https://drive.google.com/file/d/0ByfxKCNwCdupUFJmcUYtMmVWVkU/edit?usp=sharing)
Another note - I saw a thread somewhere where someone mentioned listening to the injectors with a screwdriver, I did that and the #1 injector is quite loud/clackey while the other three are much quieter and have a more gentle ticking through the screwdriver. Maybe I just need to replace #1?
-
Sounds fine to me. I wouldn't worry about #1.
-
Ya, really....I thought you said there was a miss in there somewhere! :)
Occasionally, a delivery valve can be at fault for a very slight miss. Those are those little outlet nipples on the dist. head side of the pump where the fuel lines attach.
There is a spring, washer, and the little plunger (not sure what they are called) in there. Years ago, one of them were at fault for me. And, I never really knew if it was a piece of dirt...or weakened spring....or what. I have a lot of core pumps around and simply swapped one out.
I determined which was at fault by loosening the lines, etc. But, in a massive amount of miles driven...this only happened once for me.
I think a lot of guys would be envious to have one run this good. Perhaps, you should sell the pickup (at a core rate) to one of us to further investigate!
-
HA! I am thinking of selling the pickup but mainly because my wife and I have a kid on the way and I need a vehicle that can tote the three of us. The truck actually does run pretty nicely if I do say so myself.
Today I as I was looking through everything I checked my coolant tank and found it to be about half full of some black sludge. pretty nasty stuff - just slightly more viscous than grease gun grease. No idea what the issue is. I am assuming the head gasket since that's what most people assume here, but I just replaced the head gasket about 6 months ago. I know there is a slight "crack" in the head from the number 4 cyl. area to a coolant passage, but I am stumped again. I am really hoping I can just buy a new head and replace that gasket again, maybe do the rings while im in there and be good to go with a few coolant system flushes.
When I was in there last time the pistons looked great - very clean and no damage, the cylinder bores looked good to. I have no idea how to diagnose a cracked block either so any advice would be appreciated.
The crack is circled in red:
(https://drive.google.com/file/d/0ByfxKCNwCdupRGxURC1XTk05T2s/edit?usp=sharing)
-
The image isn't working - I am attaching it to the post this time.
If the image doesn't show up this time, here is a link to see it:
https://drive.google.com/file/d/0ByfxKCNwCdupRGxURC1XTk05T2s/edit?usp=sharing
-
That head has seen some action. :-\
I doubt oil is coming from that crack, but if you got crud in the rez, it's coming from somewhere... and that head seems kinda beat.
-
Damage must have occurred in the trip through the Van Allen radiation belt........
-
who knows where that damage came from. I almost feel a little guilty for putting it back on, but I couldn't afford a new head at the time - nor did I know how to source a reasonably priced one.
While I have people's attention though, do any of you know where I can source a new PCV breather hose like the one in this picture:?
http://www.mikegabriel.net/vw/dieseltraining/diesel_training-126.html
-
The sludge is oil leaking into the cooling system. If it is a 1.5 there is a good chance you have a cracked block through the oil passage leading up to the head. Or it could be leaking from that passage into the cooling system at the head gasket. Did the head gasket you put on have the "O" ring in it? If you had an oil/water oil cooler I would look their first, but I did not see one in the video clip. Its not coming from the crack between the valves. That is totally harmless 99% of the time.
-
The engine is an early 1.6 with the 11mm head bolts. I don't recall the head gasket having an "O" ring - do the early 1.6's have the same oil galley crack problem? I just purchased a fresh head from someone here on the forum so ill make sure to take some pictures and make sure I am doing everything properly.
I did a flush today where I removed the lower radiator hose from the radiator and the water pump. Also removed the thermostat. Connected some flexible tubing from the thermostat inlet to a garden hose and then ran another piece of tubing from the lower radiator hose mount to a bucket. Then, ran the engine and cycled a total of 15 gallons of water through. The third bucket of water came out nice and clear with just a few straggling blobs of oil.
I am desperately hoping that I don't have a cracked block. Last time I had the head gasket off it was because I found oil in the coolant - just a lot less. When I finished the head gasket job, I still had some oil in the coolant after refilling the system but I never seemed to get more than what was there from that initial fill up - and I just assumed it was residual oil from the first time I had a leak. Now I am looking at replacing the head and head gasket because I know the head is pretty worn out. I am still just stumped on the oil ingress situation.
I heard somewhere once that mixing incompatible coolants can cause a sludge build up like I had. That is what I am hoping happened and that I have a good block and maybe just the residual oil in the coolant mixed with two incompatible coolants and created the nasty stuff. I guess I will see soon enough.
As an aside, Toby, I read your nicely documented driveway re-ringing process and I am planning on using it when I do the head gasket - Thanks for the guidance.
-
Well, I suppose it could be the oval oil hole in the HG, but judging from the outlined crack and the other damage on the head, I wouldn't be surprised if there were another crack somewhere by the oil supply for the valves.
I'm guessing at least #4 and #3 intake valves were replaced. Clearly, there were pieces of something getting smashed into the head and if it were a valve the damage might be much worse. Maybe debris got sucked in? (Not a turbo, so not likely an exploded impeller.) But if a yahoo ran it without an air cleaner, who knows what mighta got sucked in there.
-
TylerDurden - That is what I am thinking. I have to leave the engine together for at least another week while I wait for parts to come in and because I need to drive in that time, so I will keep an eye on everything and try not to blow it up until I can crack it open and have a look.
On another diagnostic note, I changed the oil and aside from it being sooty, it seems clean. As in no water seems to have gotten in to it. So, at least I am probably only dealing with a one way leak with oil going into the cooling system somewhere.
-
Well, I suppose it could be the oval oil hole in the HG, but judging from the outlined crack and the other damage on the head, I wouldn't be surprised if there were another crack somewhere by the oil supply for the valves.
I'm guessing at least #4 and #3 intake valves were replaced. Clearly, there were pieces of something getting smashed into the head and if it were a valve the damage might be much worse. Maybe debris got sucked in? (Not a turbo, so not likely an exploded impeller.) But if a yahoo ran it without an air cleaner, who knows what mighta got sucked in there.
Are those marks cracks, dings or merely corrosion?
-
Have you seen similar? I've seen a bit of pitting around the water pump boss, but not by the valves like that.
-
Have you seen similar? I've seen a bit of pitting around the water pump boss, but not by the valves like that.
Me neither. ;D
My GTD has corrosion like that behind the plastic upper rad hose connection, and I've seen corrosion right on the edges of the water passages on heads under the gasket.
But this is in the exposed area of the combustion chamber...
Unless there was a period of time where the engine was left in the damp I suppose.
-
I have no idea how those marks got there. It was like that when I opened it up shortly after buying it. I am cracking it back open tomorrow afternoon so I will make sure to take more pictures to document everything.
-
oh and they are more than just marks - they were full on dings in the head. Like hunks of metal removed from the metal.
-
The image isn't working - I am attaching it to the post this time.
If the image doesn't show up this time, here is a link to see it:
https://drive.google.com/file/d/0ByfxKCNwCdupRGxURC1XTk05T2s/edit?usp=sharing
Very strange! If you look at the mark at about 2 o clock that is right next to the valve. If it is impact damage why has the displaced metal not buckled the machined bit next to the valve insert?
In the picture the holes look quite jagged, and almost like crystalline casting defects.
Have you previously seen this head without the damage?
-
Mark, if I am understanding you correctly, you are looking at the right-most valve and two o'clock is on the top right side (or the crack between the valves is at 9 o'clock). If that is the case, I think that mark is just a bit of carbon buildup. Its the marks below the valves that are the major damage areas.
That said, I am surprised that the head has held up as well. The holes are definitely jagged, but wouldn't you think that crystalline defects would be much more...geometric? Flat edges allover would be more characteristic of that sort of failure right? These marks look more random...like gouging from something getting into the cylinder...I think?
I am definitely looking forward to re-examining the head.
-
I'm thinking sloppy weld repair of previous foreign object damage, harder to see because the high spots have been milled.
-
Mark, if I am understanding you correctly, you are looking at the right-most valve and two o'clock is on the top right side (or the crack between the valves is at 9 o'clock). If that is the case, I think that mark is just a bit of carbon buildup. Its the marks below the valves that are the major damage areas.
That said, I am surprised that the head has held up as well. The holes are definitely jagged, but wouldn't you think that crystalline defects would be much more...geometric? Flat edges allover would be more characteristic of that sort of failure right? These marks look more random...like gouging from something getting into the cylinder...I think?
I am definitely looking forward to re-examining the head.
LOL
Sorry about that. Every time I clicked on the picture it enlarged and focused on the Left valve. I couldn't even see the other two valves, and as the pic wouldn't scroll, I focused on the smear of carbon ;D. Opening in a new window has changed my perspective somewhat!Major historic ding.
Crack between the valves is normal and insignificant. The gouging probably more cosmetic than anything that leaks. I'd check valve operation by pouring kerosine into the ports behind the valves to see if they seal.
The 'crack' that you have outlined for everyone but me to see, does seem very straight and looks like it could be a scratch, from the milling/grinding process as it appears to be in exact parallel with some of the milling marks nearby. Does it leak? Well maybe although a fiber gasket will probably fill it.
I might be inclined to get some strands of annealed copper wire and gently hammer them into the length of the groove 8)
-
While the scarring on the head above the piston may be superficial, I'm wondering if the cause of the scarring also caused serious damage. The sludge in the rez is coming from somewhere, and the outlined crack (if it is a crack) is not near an oil passage, if I recall the design of the head properly.
-
I don't have enough to go on, but would suspect just a botched head gasket job. The outlined crack goes to a coolant passage and there should be no oil pressure anywhere near it. I would guess someone putting a head on that looked like that one was either in a really bad spot, or would be the type of person that could have a bad install of the head gasket and cause it to leak.
-
A combustion leak to coolant corrodes everything in the cooling system, including the oil cooler....which you can pressure test failrly easily.
-
I'm thinking sloppy weld repair of previous foreign object damage, harder to see because the high spots have been milled.
X2 /\
I agree 100% with the above. Also, what appears to be a crack may actually be a cut from a not-so-good mill job.
-
Well fellas, I pulled it all apart and here are some initial photos.
Here is the head after wiping all the wet oil off the surface, but prior to any other cleaning:
http://sdrv.ms/1bbnSnH
Here it is after just scraping off the carbon deposits with a razor blade:
http://sdrv.ms/1bbnXHY
The crack that was circled in red in the earlier pictures of this post is here:
http://sdrv.ms/1bbob1J
http://sdrv.ms/1bbojOV
When I look into that coolant passage, you can see the crack line for a good 2mm up into that passage. Maybe that was my problem. There are also plenty of other little cracks along machine marks that look like they could cause issues for me too, but this seems like the most leaky crack since it isn't along a machine mark.
Also - sorry that these are just links. I am not clever enough to figure out how to get direct links to the image files so that the forum can display them embedded in the post.
-
So what's your plan, a new or rebuild head?
I ran across this. . .
http://inlandempire.craigslist.org/ptd/4289213684.html (http://inlandempire.craigslist.org/ptd/4289213684.html)
-
Nice pix... it can really be seen how #4 is really an outlier.
The cause of the damage may be moot... bustid is bustid.
-
I'd be inclined to fill that crack somehow, as it's so fine, and should be easy to 'clog up', solder,weld etc. The head looks pretty flat otherwise....
-
VS. heat expansion and peak combustion pressure, I think not. You can get it welded it up but it will cost more than a new head.
Is that another from 1:00 on #4 intake to the bottom of the prechamber?
-
...Is that another from 1:00 on #4 intake to the bottom of the prechamber?
If it is, that's much closer to the main oil passage that runs along the head. Still quite a way tho.
-
Anyone ever used Al MIG?
-
Yes and it would be a bad idea for repairing cracks. High deposition and low pen.
-
Yes and it would be a bad idea for repairing cracks. High deposition and low pen.
H'mm I bought a coil of it for my MIG and never got round to using it. Wasn't there a reverse polarity issue? Hard to believe a little non structural crack can't be filled. Wattle and Daub probably do it
-
easy as
1
(http://pics.tdiclub.com/data/3697/medium/IMG_1576.JPG)
2
(http://pics.tdiclub.com/data/3697/medium/IMG_1592.JPG)
3
(http://pics.tdiclub.com/data/3697/medium/IMG_1652.JPG)
http://forums.tdiclub.com/showthread.php?t=175661
but unless you have a rare or special head, why?
-
What kind of tooling does one use to hold a head in place on a milling machine? It isn't as simple as just clamping it in a vice is it? What surface do you square up to when you have a semi-warped head, or a welded face?
-
Brown, dude.....get your hands on a viable cylinder head....stop listening to the usual mindless dribble, and get on with your life.
Clearly the old head had the crap traumatized out of it. Box it up and ship it overseas.
Thank you.
-
What kind of tooling does one use to hold a head in place on a milling machine? It isn't as simple as just clamping it in a vice is it? What surface do you square up to when you have a semi-warped head, or a welded face?
Sand paper and 3 sheets of plate glass will do it on the kitchen table. This will machine the inconel as well.
Stick it on a banana boat to me and it will live again. ;D
Even silicone pressed in with a dinner knife would seal that crack
-
I have a new head. It is at the machine shop now getting checked and cleaned up.
Turns out the engine has been rebuilt at least once before. The pistons are all 76.98mm diameter which, according to the bently, is the repair stage 2 oversize. It really put a damper in my plans because I had ordered parts based on the assumption that everything was stock sized. Now I am having to wait on new rings to get here and I need to make sure that I don't have to order oversized connecting rod bearings as well.
I guess I should just be thankful that disassembly has gone well.
I am off to do some honing. Mark, I was tempted to use your waterbottle hone - but I caved and got a ball hone instead.
-
also - does anyone know the thread pitch on the 11mm head bolts? I want to get a tap to clean out the bolt holes.
-
My gauge tells me 1.5mm.
-
I have a new head. It is at the machine shop now getting checked and cleaned up.
Turns out the engine has been rebuilt at least once before. The pistons are all 76.98mm diameter which, according to the bently, is the repair stage 2 oversize. It really put a damper in my plans because I had ordered parts based on the assumption that everything was stock sized. Now I am having to wait on new rings to get here and I need to make sure that I don't have to order oversized connecting rod bearings as well.
I guess I should just be thankful that disassembly has gone well.
I am off to do some honing. Mark, I was tempted to use your waterbottle hone - but I caved and got a ball hone instead.
I've found some really interesting info on honing/deglazing that actually kind of cooberates some of my honing premises. It also goes on about a technique called Superfinishing. Apparently invented by some two-bit little company over seas... Wait a minute... rereading I see they were called Chrysler of America.... Never had anything of theirs, unless my 1970 Vauxhall-Bedford CF is related ;D
-
easy as
http://forums.tdiclub.com/showthread.php?t=175661
but unless you have a rare or special head, why?
745 thanks for the interesting link... Actually 1.6 heads are becoming rare over here as we become flooded with TDI. More AAZ's than 1.6's on Ebay now. Mind you Brownni's 11mm head is a rare beast, especially to have survived 2 rebores!
I've found something too. MIG Al seems quite possible on sheet if heatsink used.TIG clearly preferred given a choice. Not much penetration required on that one head crack, and filling head with water would probably protect it.
Strangely I suddenly thought of the possabliity of MIG brazing. I'd never heard of it, but looking in the margin low and behold he'd done it!
http://www.mig-welding.co.uk/learning-mig.htm
-
Survived being a relative term, and the initial incident may have scored the bore bad enough to require 2nd OS right off the bat.