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Engine Specific Info and Questions => IDI Engine => Topic started by: Mohatanous on February 22, 2024, 09:21:05 pm
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Hello all!
I am new to the VW Diesel world and just picked up a 1983 Rabbit. The individual I got if from said that it had been running about a year ago but tried to crank it and it wouldn't start. Upon having it looked at they saw that the air filter had been chewed on by mice and didn't even try to start it afterward in fear of damaging things. I bought it and got it home and before cranking it I put a socket on the crank pulley to make sure the motor would rotate freely before trying to start it. It makes it nearly one whole rotation then stops and will not budge. It does this in both directions and stops in the same spot. I am not familiar with these engines yet, and am curious as to what I may be getting myself into and what the best course of action may be. Any advice would be great!
The person before me had been running it on vegetable oil at one point, and then apparently a fuel valve had went bad resulting in diesel pumping back into the vegetable oil tank, so I believe that's why they originally parked it. It seems to me that perhaps somebody tried to start it with ether or something and it skipped time, causing catastrophe. I'm not sure though, so i am asking the professionals. Thank you in advance!
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DO NOT TRY YOUR STARTER ON THIS YET!!!
Get it checked for timing, that means you need to pull the valve cover and align the cams if you can. Lobes of the first or last cylinder, #s 1 and 4 should be in the horizontal position. The IP plug should be able to get in the timing hole. I use a 3/4 inch carriage bolt for that pin. The plastic plug on the end of the engine needs to come off so you can see the timing mark for TDC.
Watch some U Tube videos, and GET A BENTLEY MANUAL, it will be used well in the future. But if this engine has jumped time and you hammered that valve with the piston it will be toast. It may already be that. IF not the clearance between the valve stem and the cam follower will be off. Measure that if you can.
Don't want to alarm you but you are wading in potential doo doo here. So many times I have read or heard of valves kissing the piston because of a poor timing belt job and it just shouldn't happen. If the timing is off you will need to loosen the cam nut and get the pulley to spin freely. Tapping it with a punch from the back to the front is normally the best way to do that. The shaft is beveled with no keyway to keep it in place.
IF the pulley isn't free when you go to put the belt on if replacing it you can't line it up right and will fight forever trying to do so. Moving the pulley with the IP solid and the crank at TDC is what makes it all go smoothly. Then when tightening the belt with the tensioner you will see it move slightly as well.
Best of luck, Not a good beginner story but you can keep out of trouble by making sure it rotates freely by hand four times around. You were mechanic-smart trying to see if it would roll over by hand instead of hitting the starter.
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Thank you for the information! I had a feeling it wasn't a great sign and that a catastrophic timing issue may be the culprit. If it is a worst case scenario, what would the rebuild process look like, and would it even be worth it or should I look for a new engine? I appreciate the guidance!
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Say you time it up and the engine turns over by hand ok. But it won't start or it smokes like a bad cigar once it gets running.
You might try a compression check on it before you even get to the START PHASE. I say that because it would let you know if you have a cylinder with a valve problem. Diesel engines need a different compression tester than you find at Autozone or ORielys for rent. The good limit on a diesel cylinder would be around the 400 psi mark. Gas engines are much lower. They fire with spark plugs and diesel fire without, because of the higher PSI in the cylinder. But you may already know that.
So say you do a check and one cylinder comes up in the upper 370-80 range. Not good and suspect to me. Time to pull the head. Not a hard job but tools are needed that you may not have. Older engines use torque to yield head bolts that would need to be replaced to get them to go back together. A new head gasket is required, as well as coolant since you don't have any idea if it is good or not. This is just for starters.
You might figure in a new timing belt and tensioner as those might be worn out and you will have them off. A Bentley Manual will pay back dividends here doing this type of heavy-duty work. To repair the head you will need new valves, easily found on Rock Auto or maybe Parts Place. A new head is harder to find and probably would need a machine shop visit to make it right. You will be pulling hoses off the engine and those if badly weathered, rat-chewed, or otherwise brittle will need to be replaced.
Getting a different engine is a crap shoot as well. You could buy one and unless the seller rebuilt it you will be looking at most of the same work but the engine will be out of the car. Big deal, it is still money to be spent and then what do you do with the other engine? How do you get it out?
I ran a diesel Rabbit on Veg oil for about a year and finally just quit doing it as the price for diesel dropped back down to a reasonable level. With diesel up to that high level again it might be worth it to you to find a seller of processed WVO and get your system to work properly. They can be a pain to maintain, and poor installation only equals poor performance. I had mine dialed in pretty nicely and still gave up using it as diesel prices dropped.
I pulled all that stuff and it is in my shed now. I sold the rabbit without it and I likely won't put it on the pickup I now own. I would not gain any savings from doing so and only lose time working on it when I should be doing bodywork instead.
I have done several head/gasket rebuilds on the VWs I have owned but I am mechanically inclined and know what I am doing with the 1.6 engine. It may be better if you are not to shop around for a good diesel mechanic and get a price from them. Labor is super expensive these days for anything from burgers to buildings so I hope you got the car cheaply.
Later
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I'm mechanically inclined and have done a decent amount of work on gas motors, but not diesel's. If it's worth it to tear into it, I definitely will. I have the Bentley manual on the way! I appreciate the feedback and knowledge, and will be back with my findings when I tear into it. Thank you!
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I think it's a good sign that it stops.
When I broke a timing belt it just kept going around.
Timing cover off first. Check the belt.
Turn the engine to TDC and look through the timing hole in the trany. Compare it to the marks on the injection pump sprocket.
Upgraded rubber valve cover gasket available. Comes from a MK3 gasser like a '94 2.0.
The valve cover studs need to be changed too.
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Update:
Upon digging a small amount more into the issue, I managed to get the camshaft to the position it is supposed to be in, but upon trying to turn the motor to the TDC mark on the flywheel view port, it will not go to the "0" mark, as that is where it is sticking. I'm suspecting there are bent valves and that the head now needs to come off, so that is my next step. What else should I check after pulling the head off? Does anybody have suggestions for what I should do if I get the head and valve train redone? Any recommendations would be great!
Thank in advance!
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Also, I'm not sure what this may mean, but when turning the camshaft it would not turn smoothly, but rather would move in sudden bursts, sort of like hitting compression. I'm not sure how to describe it, really. Thanks!
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It might be a piece of nut shell in there, from the mice in the air filter.
Or a dead mouse.
A bent valve might show itself with the valve cover off, looking from the top.
Can you tell what cylinder it is? So you kinda know what valves to look at.
1 and 4 TDC, or 2 and 3 180 from TDC, then what valves are open.
Great idea to turn the engine by hand first.
Might want to try turning the cam too.
Maybe pull the intake first so more stuff the mice left in there doesn't go into the engine. That won't cost anything, the intake gasket probably won't fall apart.
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If the mice left anything in the intake and it got pulled into or fell into the cylinders then You need to pull off the intake from the back of the engine and put a shop vac on each cylinder and rotate the crank back and forth to see if you can pull anything out of there. You might pull the glow plugs or injectors off so you can get air in from the underside of the head and suck it off the valves.
Just my thought on it. If you have one of those chip/sawdust collectors that go between the shop vac and the end of the hose use it. That way you will be able to tell us what and how much crap you had in there messing with your start-up.
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After pulling the intake manifold off I was able to see inside a bit with a camera I have for peeking into small places like that. I was able to see all the intake valves moving freely, and all of the exhaust valves also appear to move freely and without sticking from the top when I turn the camshaft by hand. I was able to see the pistons coming up to the top of their rotations on each cylinder, but it still does not turn a full rotation. Pulling the injectors and glow plugs out and a combination of blowing air with a vacuum on the intake valves has not helped the issue, (I made sure that the intake valve for each cylinder was open while I had the vacuum on it to make sure any small crap may have been sucked out). I did not see any debris in the cylinders from my viewpoints. At this point I suppose my next step would be removing the head, although now I wonder if it could be something in the bottom end?
The saga continues!
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Also, when looking up parts for this, is this a reliable site?
https://www.partsplaceinc.com/amfinder/?find=1983-rabbit-1-6-d-153473991&p=2
I typically use Rock Auto for all my other things, but didn't know if this site would be decent for things Rock Auto may not have.
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Ahhh too bad some stuff didn't fly out and then it turns.
No, I have had several friends who got burned by parts place.
Try fcp euro or maybe autohaus AZ.
Rock auto is a good place.
Did you figure out what cylinder is stopping the piston?
I wonder if the flywheel was put on wrong.
Been a long time since I heard of someone changing the clutch and screwing that up.
While the injectors are out see if you can confirm the TDC mark on the flywheel is at TDC.
Maybe feel where the piston is as the valves are opening.
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Less of a problem to check the bottom side than to pull the head. Loose crank caps perhaps.
Odd that you didn't suck anything out of the cylinders but then maybe the mice didn't get very far with their chewing and stashing work.
I'd pull the pan.
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Update:
Pulling the pan yielded no results other than finding a very dirty oil pan, which appears to have been leaking quite a bit. My next step is to pull the head and see what's going on. Maybe it swallowed a valve that I can't see or something else going on in the cylinders that I can't see. I may end up doing a rebuild of it at this point, it would help me really learn about the motor and I think it could be an adventure.
To be continued!
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They do make a rubber oil pan gasket,.. from a gasser 2.0 block maybe 93-99.
valve cover gasket from the same engine too.
Yep, you tried everything else I can think of. Might be time to pull the head.
It'll be interesting to find out what's going on.
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Owning a VW is always a continuing adventure. Keep us apprised and don't forget pictures. We love pics.
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here is the pan gasket i'd get. usually if you look up a pan gasket for an aaz car you will get this one. FCP euro has it cheaper but there website isn't working right now
https://www.urotuning.com/products/oil-pan-gasket-w-baffle-pre-1999-4-cyl-037115220b?currency=USD&variant=8392294989879&utm_medium=cpc&utm_source=google&utm_campaign=Google%20Shopping&stkn=334b6bf4d9c9&gad_source=1&gclid=EAIaIQobChMIrI_25ODkhAMVXVxHAR3mTQL7EAQYAyABEgL8W_D_BwE
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Update:
After removing the head, it appears that nothing is broken or bent! I will link a Google Drive link at the bottom of this post with images of my findings.
What I found was a good amount of gunk that was carbon-y crap built up that physically prevented the piston in cylinder 1 from completing a full rotation. After head removal, the bottom end moves freely with no issues. The valves in the head appear to be fine and all still move, so I don't think there was any catastrophic failure of two objects trying to occupy the same space at the same time.
It appears that the head gasket was blown around cylinder 1, was leaking, and then perhaps the car sat for a time and the gunk built up to that point. I'm not sure, but I know that the cooling system is in terrible condition. What it seems to me is that nobody ever used distilled water in the system and the deposits and gunk inside show that. My prediction, and it is only that, is that over time the gunk buildup made the engine run hotter than it should, popped the head gasket, the person parked it, and just left that information out when I bought it. It would definitely explain why they sold it to me for such a low price. What could have also happened is perhaps a heat exchanger in the WVO system leaked some crap into the cooling system and caused the issues. Either way, I don't see any signs of anything that can't be saved, so I'm a bit relieved. The bore on the cylinders are not scored, so that's good.
My plan is to go through this thing while I have it all apart and put it back together properly and with as many upgrades in terms of reliability as I can. I'm not looking to find performance gains and make tons of power or anything, I knew what these engines were capable of when I bought it and I'm not crazy. I know they're pretty bulletproof and reliable as long as they're treated well, and that's what I'd like to do. I plan on completely replacing every part of the cooling system and flushing everything thoroughly. While I have it all apart, what else should I do? I don't know if the injection pump leaks, but I don't know if I should mess with it before seeing if it does or not. I have a friend that is excellent at doing head work, and I plan on having him look at the head, cleaning it up, and making sure it's flowing as best as it can before I go putting it back on. I also have another friend that has a short block in case I need it, so that's great.
I also do plan on trying a WVO system again some day. I have a friend that owns a restaurant that said that I could take some waste oil once a week, and I think that would be pretty neat. I have lots of friends, which is helpful.
I look forward to responses, once again appreciate everything that any contributors have said thus far, and if I am incorrect in my plan or should do things differently, please let me know. Thank you all!
https://drive.google.com/drive/folders/1Ov7h4FqBKjtB_mPMnzr1qOJV4M_LhD9j?usp=sharing
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Good to know all of this.
I ran WVO in a Rabbit for a while and then the price of diesel went so low it didn't pay to run it. I think it would now. I also ran two hot plates for the oil warming up. One right before the IP and the other just before all the filters. I didn't like the temperature drop I had going with the Racor filter. I had individual temp sensors on the inlet and filter areas. They were pretty cool blue looking things that ran on 12 vdc.
Thanks for keeping us up to date. Enjoy the cleaning and rebuilding. Next stop, Getting it to run.
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I always like to check the I-shaft bearings.
They can't be changed without dropping the engine but they will cause low oil pressure if they are bad.
The timing belt should be changed and that would be a good time to pull the I-shaft out and take a look.
The oil pan gasket linked above might be a little overkill for an old NA Rabbit.
But it's nice to see they are cheaper than they used to be. They were quite expensive for awhile.
I think they have to fit on over the oil pump, then the pan gets put on. Been awhile since I installed one of them.
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As far as baffled oil pan gaskets this might be another alternative that appears to be in stock but don't know about the quality:
https://www.ebay.com/itm/124316760833
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definitely overkill for that engine, but theyre not very expensive and theyre easier to install and remove. I have seen people claim performance and mpg benefits, which i am sure there are benefits but i doubt it is something you'd be able to easily notice among all the other factors that affect those 2 things.
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Update:
I haven't had a lot of time to work on my car lately, but my head guy found that there were two cracks in the head between the valves on cylinder's 1 and 4. I'm going to have the head fixed and then pressure tested to ensure that it will be usable, so by the time I get it back it will basically be a brand new head.
Should I do piston rings since I'm getting the head redone to this degree? If so, anywhere specific to get good rings? Thanks in advance!
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those cracks are usually normal.
I'd consider the condition of the engine as a factor on whether or not i'd do rings. they're cheap to do while you're in there though.
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Right, those cracks are normal.
Surprised you only found them on 1 and 4.
Get a machinist that knows VWs.
Don't let him surface it. Find out what "fix it" means.
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I used the glass plate and very fine, like 400 grit paper with oil, and got my head to come into tolerance. So I think as long as you are careful with the precups on a machine you would be OK. True or Not True?
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My concern is if you surface it flat, the cam will rock when it's installed.
It will be pushing down very hard on the center journals as it runs.
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Brief update:
I have not had any further work done on the head due to my friend unfortunately having a stroke. At this time we don't know if he will be alright or not, so that just plain sucks.
In the mean time I've started cleaning the block out of buildup and replacing the heater core. One other thing I have to tackle is the bearing on the steering shaft inside the car. That seems like a fun task!
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Is the pickup AC or not?
There is an easy way to change the heater core in an AC car.
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i believe there is a nice kit for the steering column bearing these days.
in the past or just for a temporary fix many just push it back into place and then use a hose clamp to hold it there.
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Yeah, pulling out that steering column is a bite. Mostly due to the knuckle thing that always seems to be tighter than it needs to be.
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And the flying flat springy thing.
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OH YEAH, I forgot about that. Toughest thing to install on a VW I believe. I may not be able to get one back in with the lack of hand strength these days.