Adding UV leak detector dye to oil to find leak

srponies

Well-known member
Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
I just rebuilt the motor on my '02 Jetta. An "in car" rebuild with new bearings, rings, Franko6 head rebuild, all timing components, injectors. I've driven it about 50 miles. It runs great - but, I'm finding a small amount of oil at the rear corner of the head (beneath the EGR). I went to the car wash yesterday to spray it down so that I can check for fresh oil.

fyi - I did not replace the front crank seal (that may be the problem now).

I am going to do a close inspection of the areas to track down the leak. If I can't spot it easily, I was planning to add UV dye to the oil to help verify the leak location. But - will that compromise the oil?

Any other tips here for tracking the leak down?

I need to tackle this now before it gets near the timing belt and the $$ goes up. The car is not being driven - but I need to fix it asap.

I don't feel it's a hard job to replace either the cam or crank seals, just tedious. Maybe I should just dig in and replace them both. Although since the cam seal is new it shouldn't be leaking.

Thanks for any ideas,
Steve
 

Ski in NC

Top Post Dawg
Joined
Jul 7, 2008
Location
Wilmington, NC USA
TDI
2001 Jetta ALH 5sp stock
The uv dye will not tell you much. Standard technique on a clean engine is to wipe up with rags, using sticks to get in tough spots, and watch. Whether the oil glows with uv or not doesn't help too much.

Typical leak paths are where cam bearing cap split holds seal, there needs to be a dab of sealant under cap..also cam cover in the corners around bearing cap.
 

Powder Hound

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Joined
Oct 25, 1999
Location
Under a Bridge, Crestview, FL, USA
TDI
'00 Golf 4dr White 5sp, '02 Jettachero 5sp, Wife's '03 NB Platinum Gray auto(!)
Yeah, right there in the corners. Same deal at both ends of the cam. And the vacuum pump can sometimes ooze - there isn't a lot of pressure on the seal for it, so if there is any foreign material in those grooves, you can get a leak there, too.
 

srponies

Well-known member
Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
Ok well I'll just clean (better) and watch. I did find this morning that the turbo (return/drain) line was seeping barely. Also wet around the lower intercooler tube connection (the one with the snap ring). I'm going back to the car wash because the back of the block is slightly gritty.

I'd spray the area behind the upper rear timing cover with brakleen, but I'm not sure if it'll get on the belt or not.

The cam cap and cam cover both got dabs of sealant. Always possible they are leaking. Just hard to tell in that area. Makes me wish the upper/rear timing cover was removeable without taking everything else apart.

Thanks.
Steve
 

s4phillips

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Joined
Jul 3, 2005
Location
Live in d/FW, TX. Transplanted from the Pacific
TDI
2002 Beetle, 2005 Passat Variant-DOA blunt force trama, 2014 Beetle-went home
Another [very old] trick to find an oil leak is to coat the suspected area with a light dusting of talcum powder after the engine is clean and dry. Start the engine and watch. The powder coating tells you quickly if and where you have a leak. May be able to find a powder based anti-perspirant spray that will also give you the powder coating. Keep the powder away from your air intake, oil fill cap, dip stick, rollers, etc... Once the leak is located, the talcum powder should just hose off.
 

Dodoma

Veteran Member
Joined
Mar 30, 2004
TDI
2002 Jetta White
Sometime the leaks are not where you suspect. It could be a leak above that area and oil just seeped over the suspected area. If leaks is at the corner of head/block, apart from camshaft, egr, valve cover, vacume pump seals, it could as well be head gasket. If you see one or two drop, then it is most probable crank, or cam. If it is a lot, it could also be from oil pan. Put a piece of napkin where you suspect. If it get soiled with oil, then that is the culpit. You do by process of elimination. The most hard is when you have oil leaking from the bellhousing/engine which could be either main crank seal, oil pan, or other.
 

srponies

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Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
I did some more cleaning and then let it run while watching the area. Took just a few minutes for the oil to drip down to the rear corner of the head. I shut it off, and used a mirror to check. I was able to view thru one of the lower cam pulley "windows" and saw a drip under the cam.

Took the belt/pulley off and found the source.






I was carefull when I installed the seal - apparently not enough. I'll remove the seal today and check out the sealing edges.

Steve
 

visionlogic

Veteran Member
Joined
Aug 23, 2006
Location
Daphne, AL, USA
TDI
2002 Jetta TDI
srponies said:
I was carefull when I installed the seal - apparently not enough. I'll remove the seal today and check out the sealing edges.
If it's one of those new super-duper teflon seals it needs to be installed completely dry onto a dry shaft, and then left in place undisturbed for 4 hours or so in order to 'seat' properly, or it will leak. I hate them.
 
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srponies

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Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
The part # for this one is: 038 103 085C . I'll have to check which it is. I'll be picking up a new seal today.

BTW - which one would be a better seal (when installed properly)?

chrome - Yes to all.
Thanks.
Steve
 
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visionlogic

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Joined
Aug 23, 2006
Location
Daphne, AL, USA
TDI
2002 Jetta TDI
038 103 085C = teflon (PTFE) seal

Quote, from WordImpex.com: "**Update PTFE Seal Lip Design, No Spring Located Behind Inner Seal Lip***Proper Installation Instructions Included Must be Observed to Ensure Proper Seal and to Prevent Premature Failure. Installation Surface MUST be Clean and Completely Dry. DO NOT USE ANY OIL or GREASE on Sealing Surface. In order to ensure a secure seal, the motor should not be operated for at least 4 hours after installation so the PTFE sealing lip can be evenly positioned around the shaft being sealed**"

The old school seal does have the traditional spring tensioner around the inner lip - part number 038-103-085-E.

As far as which one "would be a better seal (when installed properly)?", I don't have any facts to support one over the other, but I imagine that differences would be statistically insignificant. However, for me it's the "installed properly" hurdle that's the tripwire... a 4 hour wait for molecules to align themselves is not something that enhances my serenity.
 
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srponies

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Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
well interesting that the seal itself has 038 103 085 F on it. It is the teflon - with rubber outer surface/lip & plasticy inner lip/seal. The inner seal appears deformed to me, and almost like it was fatigued (when you bend plastic back and forth numerous times) along the lip about 1/2" long.

I'm not sure if the improper install (prelube the seal lightly with oil) would cause all of that.

I'm almost inclined to go with the spring backed seal, as I would think that it would use the mechanical means (the spring) to hold tension no matter if the cam moved or not (within reason/spec).

Steve
 

srponies

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Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
Quote"The old school seal does have the traditional spring tensioner around the inner lip - part number 038-103-085-E."


I'm not sure about the part numbers. the "085-E" looks like it's used as the front crankshaft seal. But it says it's 48 x 10, compared to the 47x10 cam seal.

Steve
 
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visionlogic

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Joined
Aug 23, 2006
Location
Daphne, AL, USA
TDI
2002 Jetta TDI
You are correct Steve, my error - the PN I cited is indeed a crank seal. I don't know if the old style cam seal is even still available. Maybe a guru will chime in.
 

srponies

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Joined
Feb 15, 2009
Location
Trevor, WI
TDI
02 Jetta GLS, 01 Beetle
Just some closure on this for now (fingers crossed/knock on wood). I went to the local NAPA with the leaking cam seal - they cross referenced the number on the seal, and also looked up the application.

I ended up with an SKF seal - Part #12733. It is slightly narrower overall, and is a spring-backed seal. Dimensions are 47OD x 32ID x 7 wide. Reassembled with no problems.

I've put on about 75 miles, and no leaks yet. I'll be checking periodically, hopefully all stays well and dry.

Thanks,
Steve
 

TDI_Votex

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Feb 28, 2004
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St-Hilaire, Qc, Canada
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Bora Votex, 2003, Gris Platine
I have a 038103085C from Victor Rienz in hand, and this is the included instuctions. Clic to have full size view. This one come with a pre-installed sleeve that will facilitate insertion on the cam shaft end.
 

anthonynoahan

New member
Joined
May 24, 2012
Location
anchorage,alaska,usa
TDI
not yet
This is the major problem with my engine, After cleaning the engine as suggested in one of the post, I hope better spraying the talcom powder around the area otherwise there is a large amount of oil leakage existed in the area. The leak detector provided is with best features and it best serves the purpose of mine. Could you please produce some more attachments about the latest updates and the special features.
 
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