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Engine Specific Info and Questions => IDI Engine => Topic started by: turbosuzi on September 05, 2009, 09:26:22 am
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I went to buy the Bently and they are out of stock. I am loking for the mainbearing clearance does anone have the spec? And should I be using the red or green plastigauge?
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Iused the red plastigauge and the largest clearance was .004in. with the old bearings. Does that sound reasonable? I will be replacing the bearings any ways.
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that seems fine to me.
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OK, the engine has new main bearings that plastigauged out at a little over .002in., replaced 2 broken oil jets, new rod bearings, new intermediate shaft bearings, and a new oil pump, 15w40 oil and new filter. After start up it oil pressure went up to 50psi then after about 2min at idle down to 25 psi then after a trip around the block it went down just below 5psi. The pressure will go up to 25psi while on the throttle but drops immediatle after letting off. My quetion is what do I look at next to bring the oil pressure back to where it should be? the only improvement is that the low oil psi light wnot come on now.
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are there any other bearings in the bottom end of the motor that you can replace? have you replaced the oil pump yet?
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OK, the engine has new main bearings that plastigauged out at a little over .002in., replaced 2 broken oil jets, new rod bearings, new intermediate shaft bearings, and a new oil pump, 15w40 oil and new filter. After start up it oil pressure went up to 50psi then after about 2min at idle down to 25 psi then after a trip around the block it went down just below 5psi. The pressure will go up to 25psi while on the throttle but drops immediatle after letting off. My quetion is what do I look at next to bring the oil pressure back to where it should be? the only improvement is that the low oil psi light wnot come on now.
are there any other bearings in the bottom end of the motor that you can replace? have you replaced the oil pump yet?
turbosuzi did you say these new readings are at the head or oil filter flange?
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oil filter flange.
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After searching for a couple of hours I found that oil pump shaft bearing, vac pump seal, and the vac pump/oil pump key way might be the next step in my quest to stop low oil pressure. Why would a bowtie shape in the vac pump gear be related to poor oil pressure?
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there is a hole through the center of the oil pump shaft and vac pump shaft. oil pump is supposed to have a nice tight fit in the vac pump drive slot. not a large amount of back and forth play with a bow tie shaped slot. i bet that right there is your culprit. oil pump pumps it right up the shaft, and then instead of oiling the vac pump, it just squirts out the bottom of the drive slot and right back to the oil pan. i bet anything...
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I don't recall seeing a hole in the shaft for delivering the oil up to the vacuum pump? I thought that the IM bearing had a groove in it to spray oil at the vac pump?
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Does anyone have a part number or name for the vac pump oil seal?
Is the oil pump bearing located whare the shaft goes up through the motor and how would that affect oil pressure?
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vacuum pump oil seal wont make a difference in oil pressure. and yes tyler, there is a hole through the oil pump shaft. the one i took out of my TD has the hole, the stock one from my 1.5 had the hole, and a couple other 1.6 pumps ive messed with had the hole. just because the ones ive seen have a hole, doesnt mean they all have them.
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It is a long shot but could you try another gauge? Every gauge I have seen always reads different, but maye that one is just a little off. Something is different since your low pressure oil light isn't comming on. Maybe check to see if the other 2 squirters aren't sticking open or that the new pump bypass spring isn't messed up. These are just guesses, but not out of the question I don't believe.
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anything that can go wrong, it will.
maybe not right now, but some time.
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Are you sure oil goes through the pump shaft? I never heard this before. The vac pump gear gets lubed by the IM shaft bearing. Good luck finding a vac pump without the bowtie wear pattern unless you buy a new one from the dealer, if they're even available.
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There is a hole but with thetype of union that is there I dont see how it would send my oil psi down so far. I think that it must get oil up into the vac mechanism seals, otherwise I dont know how oil would get up there. I will try another pump I have and let you know what happens.
Im still wondering if the oil pump shaft beaing might have anything to do with oil pressure?
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no no no, the oil pump shaft doesnt lube the gear. it lubes the inside of the vacuum pump. you remember on the ancient 1.5's how they had an oil tube from the filter flange to the vac pump? the hole in the center of the oil pump shaft replaced that design. they may have eliminated that design when they went to the vane pump tho. but the pump from my MF 1.6 had a hole in the shaft, and a vane pump. ???
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So I should look at replacing the shaft seal and the bearing? The bearing being an oil supplier to the shaft was never replaced and the motor was siezed a couple of years ago, and ran hot and high rpm a couple of weeks ago. The bearing could be non-existant.
Any tips on replacing the sahft bearing?
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no no no, the oil pump shaft doesnt lube the gear. it lubes the inside of the vacuum pump.
Are you saying "no no no" to my post? That's what I just said, the oil pump shaft sends oil up into the vac pump. The jet from the intermediate shaft bearing lubes the vac pump / intermediate shaft gears.
Andrew
no, im not saying that to you. i was just saying that the IM bearing doesnt lube the INSIDE WORKINGS of the pump. i know that it lubes the pump and shaft gears, but the hole in the shaft is for the insides. i was not aware that theres a little seal in the bottom of the gear either.
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replaced the vac pump with one that had a better seal and was not chewed up in side the gear and still the same.I get over 25 psi then it goes down to 1-3psi after about 5 min of idle. What is next the for the low oil psi saga? If bottom end is tight, IM bearings are tight, oil pump is working good, vac pump seal is good, oil jets are new, then where is the oil going? What should I look for in the head?
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can I use pliasti gauge on the cam bearings and what is the spec for them?
I didn't see if the bushing was in good shape or not but I will get one from the stealership tomorrow, I don't want to take any chances with this thing.
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There are no cam bearings.
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When you got the vac pump out did you look at the oil pump shaft bushing? To replace it, you need to pull the pan, pull the oil pump (I'm sure by now you're good at that... ;D). Then use a socket on an extension to tap the bushing out. I flip the appropriately sized socket around on the extension so the flat part of the socket is against the bushing when tapping it in to avoid marring the top surface.
You could have an assistant drive the oil pump using an electric drill and have the valve cover and oil pan off in order to see where it's gushing. Be prepared to get very oil soaked...
Do you know a part number for that bushing? You think that would affect oil pressure that much?
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the oil pump shaft bushing wont really affect it that much, but the seal in the bottom of the vac pump gear that andrew mentioned can cause problems.
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I am in town today and is my only day to get parts. Is there any thing else that you can think of that I might get other than the oil pump shaft bushing and another pan gasket? By the way I pinched the line to the turbo wile running to see if that was the culprit in my low oil pressure and it didn't make any difference in hot oil pressure. My engine has silicone transmission cooler lines running to the front of the rad through a transmission cooler to the turbo. I could see some of you cringing at the thought of some one pinching the turbo line to check for oil pressure loss.
Thanks for all of your help guys.
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Yes, it could certainly affect it that much. If oil flow were unrestricted from that galley, hot oil pressure would be zero. The seal in the bottom of the vac pump would have much less effect as the diameter of the channel in the shaft is much smaller than the feed hole of the shaft bushing. 056 103 541 is the part #.
see, i thought you meant it the other way around. sorry for the mis-information.
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use waste motor oil. then you wont be wasting anything! lol
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I ordered the bushing from the stealership today, to my suprise it was only $12.00. I wont get it until Thurs and hopefully installed on sat. I will let you know what happens.
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I replaced the bushing today and still the same condtion, 25+psi at start up then after about 10min of idle oil pressure goes down to 1-2 psi. What next? Is there anything in the head that could be loosing that much oil psi? This is my daily driver and I am really afraid to drive it.
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Did you plastigauge the rod bearings as well?
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In his first page he tells us what he has done. I think he has replaced everything but the gauge. I would check the gauge and see if the 2 oil squirters that you didn't replace are functioning correctly if you haven't done so already.
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I think today after work I will remove the pan again, valve cover, spin the oil pump w/drill and see where the most oil is leaking from. has anyone done this before and seen where an oil leak was and was able to repair it? I am worried that there might be a crack in the block some where.
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you know, i totally forgot about that posibility. a cracked block would put a halt to things.
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Should I do this when it hot because I get ~26PSI when cold.
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Thats exactly what I was afraid of. Thanks Libbybapa and Rabit on Roids you bothe have been a great help. Hopefully we will get to the bottom of this soon.
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Well I took off the oil pan and used a cntainer of oil am my wife spun the oil pump with a drill and I am not sure what I am looking for but the front main bearing starts to leak oil first then the rear then rain from all over. Any ideas on where to look and how much is too much? I will probably try my brothers in the same fashion he has good oil pressure, and see what the difference is.
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I had rebuilt a diesel about 10 years ago on an engine with 300K or so on it. I forgot to seal the oil squirters a got relatively the same oil pressure you are getting. Because it was a turbo diesel, it would start and have much higher pressure cold (about 60 or so) and only 1-2 warm. The dynamic pressure warning and buzzer would come on if you tried to drive it.
I pulled the pan and so much oil comes out of everywhere it's hard to tell anything.
You can plug the oil going to the head - by pulling the bolt that supplies it and see if that changes anything.
My result was I had to remove the oil squirters and properly seal them. Then I got roughly 7-10 psi at idle and 40-50 psi highway driving.
That's my 2 cents...
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What do you mean by sealing them? There are no washers or anything to replace. You used some kind of goo?
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The Bentley says that they should be sealed with a specific VW goo... most of us just use a Permatex variant.
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Do tell... I don't have mine together yet and may need to put some goo on it since I didn't yet. How important is this goo...I have all the piston's in :(
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Is this the regular RTV type sealant or an epoxy based product?
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From the Bentley:
Oil Spray Nozzles
Turbo diesel and 16-valve gasoline engines are equipped with oil spray nozzles which, above a certain oil pressure threshold, spray oil from the main oil galley against the bottoms of the pistons for added cooling.
Install these nozzles with sealing paste, Volkswagen part no. AMV 188 100 02, and torque the bolts to 10 Nm (87 in. lb.).
I use Permatex Ultra Copper as a sub... but Blue or Black would probably work as well... just happen to have lots of Ultra Copper. ;)
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Permatex red is my poison of choice.
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How long after I seal the oil jets can I run it? I dont want the oil pressure to just push out the sealer.