Sealing Fuel Injector Inserts

**Duchenbagen** · 01-21-2011 03:52 PM

My fuel injector inserts are leaking blow-by oill residue from the intake track on my car. I was wondering for those of you who have had to replace them what did you use? I bought the factory sealant for 65 bucks and it lasted 7K miles.

**PDX04a4** · 01-21-2011 04:07 PM

i'd also be interested in this, 2 of my seats are completely covered in blow-by and look nasty. cleaning them doesnt last very long, gonna have to pull them out and seal them. im sure having bigger injectors doesnt help either.

**kwimberly** · 01-21-2011 04:35 PM

Me too. One of mine is much worse than the others. Pretty sure there's a TSB saying that some is normal.

**jc_333** · 02-24-2011 08:41 PM

I bought new injector seals for my car as I have the same problem. Can I just replace them or is it a requirement to seal them as I couldnt find anything else on this topic.

What tool do you guys use to undo them from their housing?

Thanks

J

**diagnosticator** · 02-26-2011 04:11 PM

How do you know the screw in seats are seeping fuel and not the injector O rings? Even if the injector seat threads are sealed and not leaking, the O rings will seep a little bit making a mess in the same area, and there is really nothing to prevent this. Some seepage is normal.

**old guy** · 02-26-2011 04:45 PM

If you need to replace your injector "O" rings don't pay the dealer $4 per "O" ring. Go to Autozone and get a Sorenson "O" ring kit part number 800-9212. The whole kit is under $5 and it comes with 8 "O" rings and an "O" ring installation tool. It won't be listed for an Audi but the "O" rings are the correct size for your injectors. As diagnosticator pointed out your leakage is probably coming from the "O" rings. If the seat threads are truly leaking, unscrew them and use some Teflon tape on the threads.

**a4darkness** · 02-26-2011 04:52 PM

I need to do this, mine are all gunky too.

**dewey527** · 02-26-2011 05:19 PM

I thought mine was due to having knockoff 380 injectors...so much for the deal I got. I know I have to get the TT225's.

**pape** · 02-26-2011 09:09 PM

If you try to unscrew the injector seat from the manifold be carefull as they get brittle and can crack when presure is applied to unscrew them.

**jc_333** · 03-01-2011 06:07 AM

Thanks for the pointers.

I bought new O rings, injector seats and clips for the replacement job. However, what tool does one use to unscrew the old seats?

Thanks

J

**diagnosticator** · 03-01-2011 10:47 AM

I am not sure of the size, but you can try using a metric bolt with the head size that fits, then double nut the other end of the bolt shank. I am guessing a 17, 19 or 21 mm will fit.

**A4Maine-iac** · 02-26-2012 05:35 PM

Bringing back the dead. I have 2 seats that are new and are leaking. I did use teflon tape but no luck. Anyone use something else that worked?

Thanks - Brett

**old guy** · 02-26-2012 05:40 PM

Originally Posted by A4Maine-iac

Bringing back the dead. I have 2 seats that are new and are leaking. I did use teflon tape but no luck. Anyone use something else that worked?

Thanks - Brett

Are the "O" rings leaking or are the injector seat threads leaking?

**A4Maine-iac** · 02-26-2012 05:47 PM

Injector seats. Ran a boost leak test. Sprayed some carb cleaner and watched them bubble. Verified was the seats.

**old guy** · 02-26-2012 05:48 PM

Originally Posted by A4Maine-iac

Injector seats. Ran a boost leak test. Sprayed some carb cleaner and watched them bubble. Verified was the seats.

Use a few more wraps of the Teflon tape. Teflon is heat resistant way beyond any temps your manifold will see. Use enough to seal the threads completely.

**A4Maine-iac** · 02-26-2012 05:58 PM

Did go around 2x. Covered the thread. Maybe this stuff? Just came acrossed it.
Permatex No. 14 Thread Sealant with Teflon
Says its good up to 300 degrees.

**MmmBoost** · 02-26-2012 06:05 PM

I used Permatex Liquid Thread sealant with good luck. The white shit. It gets on everything and makes a mess but it works.....

**A4Maine-iac** · 02-26-2012 06:12 PM

Thanks. i'll give that a go and see.

**old guy** · 02-26-2012 06:19 PM

Just use a few more wraps of the Teflon tape. It's clean, it's easy and it works. We use it daily to seal 120 psi air lines, 60 psi coolant lines and 2,000 psi hydraulic lines operating at 200° F. It can certainly seal a measly 20 psi injector seat.

**MmmBoost** · 02-26-2012 06:22 PM

Originally Posted by old guy

Just use a few more wraps of the Teflon tape. It's clean, it's easy and it works. We use it daily to seal 120 psi air lines, 60 psi coolant lines and 2,000 psi hydraulic lines operating at 200° F. It can certainly seal a measly 20 psi injector seat.

only 20 PSI?? pssssssshhhhhhhttt.

**old guy** · 02-26-2012 06:26 PM

OK....How about I am sure it can seal a measly 40psi on your manifold. Would that do it??

**MmmBoost** · 02-26-2012 06:40 PM

Better!

Just don't blow the welds on the intake......

**boy412** · 02-27-2012 07:30 AM

Originally Posted by MmmBoost

Just don't blow the welds on the intake......

LOL...nothing like a Fast 'n Furious reference to start the day!

**iamshayan** · 02-27-2012 07:55 AM

Originally Posted by jc_333

Thanks for the pointers.

I bought new O rings, injector seats and clips for the replacement job. However, what tool does one use to unscrew the old seats?

Thanks

J

I've heard of people using the socket side of a spark plug tool, give it a try.
i went out and got the allen sockets that were huge. (returned them after using them) love Canadian tire.

**MmmBoost** · 02-27-2012 08:11 AM

You could also use a 17mm head hex bolt upside down with it double-nutted.

I happen to have a 17mm allen.....so that worked for me, but there are other ways of getting them out for sure.

**A4Maine-iac** · 02-27-2012 08:56 AM

^ yup got lucky happen to have both. 5/8 socket upside down with 5/8 bolt and 2 nuts.

**Charles.waite** · 02-27-2012 09:02 AM

This thread is so apropos! Bought some new o-rings and seals last week and have been waiting for some time to install. I was wondering what size hex I needed!

FYI GAP sells the o-rings for only $2 each or so. Not complete robbery.

**A4Maine-iac** · 02-27-2012 10:17 AM

Just went out and confirmed. 20 mm. Also came across this.

http://www.goapr.com/support/injectors.pdf

**MmmBoost** · 02-27-2012 10:19 AM

My bad, I guess the AEB and AMB are different. The black inserts on my AEB are 17mm

**DiertyEuroSpec** · 02-27-2012 11:59 AM

Also make sure the old plastic seats are not cracked. A couple of my seats were cracked and I could not locate a mystery boost leak until I tested the manifold side. Whalahh it was the seats. Also if you have TT injectors they run larger diameter (skinnier O-rings) than stock O-rings on the TT injectors which will crack the seats if pressed in. If they are cracked / older they also usually bond to the metal intake because of high engine temps. and make it a b*tch

to remove (not sure if factory uses a sealant on these or not). I recommend some sealant when reinstalling. Also Didn't know APR made their own cup seals... good write up

**a4darkness** · 02-27-2012 02:12 PM

Always thought it was pretty weird that APR required the use of special injector seats for their special injectors. Or am I over thinking this one?

**Charles.waite** · 03-25-2012 11:36 PM

Anyone have good ideas for getting the seats out? I've found a 20mm hex on amazon, o'Reilly's was useless as was expected, if I bring a seat into a hardware store is it eAsy to find a bolt that big to do the double nut trick? Not wanting to spend $15 on a hex driver I'll use once...

**Matt Devo** · 03-26-2012 12:21 AM

Originally Posted by Charles.waite

Not wanting to spend $15 on a hex driver I'll use once...

technically you'll use it four times, if it makes you feel better. I bought one just for this job, and would offer to lend it to you, but shipping both ways is likely to cost $10, at which point you may as well just buy the thing

**vhstejskal** · 03-26-2012 04:53 AM

Goto Home Depot and check which bolt head will fit the cloest to the seats (I believe the one I used was 1/2 inch) I then wrapped the bolt head with like 2-3 turns with electrical tape to get it to fit exactly. Put a lock washer on the other tnd and you have yourself a seat extractor for about 2 dollars. It worked for me.

**A4Maine-iac** · 03-26-2012 05:15 AM

See post # 26 also. $5 for a 5/8 spark plug socket and 5/8 bolt and 2 nuts. The flip side of the socket fit perfect. Go to autozone youll see.

**Charles.waite** · 03-26-2012 08:37 AM

Yea but that's for a 17mm seat. Our are 20mm. I figure I'll need a 13/16ths. My end of my spark plug wrench sorta fits but it spins almost 1/2 a tooth before catching so that's not really a viable option, not to mention I'd have nothing to turn it with.

I'll hit the hardware store today and see if I can Jerry rig a solution. If not I'll get the damn 20mm driver.

I wish I had a deeper toolchest because it seems like every time I do some repair I need some sort of specialized tool or another.

**evo_ski** · 03-26-2012 08:53 AM

Charles, where did you snag your injector seats from and what did you pay? I was going to do mine in a few weeks. I snagged o-rings, but now I figure while I have them off I should swap those as well. I would be willing to toss you a couple bucks to borrow that special socket if you did end up buying it.

**Charles.waite** · 03-26-2012 09:30 AM

I believe I got tem on GAP. Weren't too pricey if I remember.

I may just get it, but if I jerry rig up a bolt/nut solution I'll definitely let you know what I used. And let you have it if you need to use it. I don't envision needing to do this more than once while I own this car (assuming they seal correctly the first time that is).

How do you guys stretch the o-rings over the lower injector cap thing? Can you heat up the o-rings in hot water to make them more pliable? My injectors seal perfectly to the rail, so I'm only replacing the lower o-rings.