Two injectors blowing bubbles after head replacement.. How to seal them.

[rumbling_caddy]

I found out my old 1.6td head went bad...Cylinder #1 didn't fire and exhaust was coming out of the coolant flange, Lol

Anyways I got my caddy going again by installing a used 1.6td head and replacing valve stem seals and injector heat shields while I was in there.  The engine is all back together now and running on all four cylinders with no oil or water leaks...



However I noticed bubbles coming out of two injector ports.  The hard to get to ones behind the IP.   Maybe I cleaned out the threads too good?
All injectors screwed in smoothly and were  torqued to 53 lbs..

Am I supposed to seal the injector threads with something?  What is the recommended product or procedure to seal the injector threads?

Thanks in advance

[ORCoaster]

I read this twice and I don't read anywhere that you used new or re-cupped heat shields.  You have to bend the middle of a used shield back so that the inside meets the middle and you can see a slight fingernails gap around the outside of the shield.  Then when you reinstall the middle touches first and the edges seal second.

Did you use a 27 mm socket and extension to put them in?  Is 53 lbs correct?  I am thinking 70 but that might be the newton meter number. 

Every time I see that symptom I find the shield was not reset correctly so there is a gap that is letting the compression weep out. 

In order to really get in and square to the injectors I pull the fuel lines loose from the pump and get rid of the clamps.  That allows them to swing out and get out of the way.  Then I make sure I am always square to the head and pushing toward it rather than pulling away from it to keep from breaking off the lip of the boss that holds the injector in place.

The only thing I put on the threads is a wee coating of anti-seize.

[rumbling_caddy]

Yes I used new heat shields. The old heat shields where stuck in there real good. I used a big screw and lots of brake cleaner to get them out. Maybe I didn't clean out the gunk in there that well before before dropping in the new ones. I only really double checked they are not upside down, lol

[libbydiesel]

This is completely normal and absolutely nothing to worry about.  You spilled diesel into the threads, it pooled at the nozzle and now after the engine is warmed up a bit it is boiling back out.  As long as no diesel is leaking, you just need to run it through a few heat cycles and it will stop.  If the return nipples are leaking (it looks like they might be), the bubbling will continue indefinitely as the leaked diesel boils off.

[rumbling_caddy]

Yes there is a lot of spilled diesel because I did the loosen the top nuts of injector lines to bleed the air out before tighten them. .  I fired up the engine for the first time today.. It started easily with glow plugs actvive.

So I should clean the spilled diesel and keep an eye open for leaks? Thanks for the tip libbydiesel..

[libbydiesel]

Just make sure it isn't still leaking.  No need to clean it up really.  It will boil off within a couple heat cycles.

[air-cooled or diesel]

you look like you have clear return lines, i find 1 or maybe more return line(s),(when their clear)can be difficult to stop leaking. its easy its a leak and its boiling off, that pic looks like my clear return leaking; the only question is it boiling off or is it pressure leak. if you tightened injectors right, only something like a defective head, like the threads will be the most likely problem, get leak stopped from line(s). when cool spray soapy water there and see if it bubbles, if not, its return leaking, and then boiling off. note motor can heat up pretty -quick and make soapy water boil. -donot over tighten injectors.

[libbydiesel]

Spraying soapy water at the base of the injector will not tell whether or not it is a leak.  Soapy water will boil off in the same way that diesel boils off. 

[rumbling_caddy]

I doubled check the injector line nuts and fuel return lines. One injector is still leaking fuel to the outside.  Might have to replace it this weekend...

[ORCoaster]

If the leak is coming from the rubber lines and you have some slack in them just nip a 1/4 inch off and re install.  Push on and get as far to the body of the injector as you can.  Then give it a slight tug back up.  That tug tightens them on the stem where it is bulging fat. 

[Blocksmith]

If one gets impatient with return lines not sealing, small zip ties work as well.

[rumbling_caddy]

I replaced the one leaky injector and all the return lines.  No more leaks or bubbles.  Thanks everyone

[libbydiesel]

Why the sad face emoticon?  Seems like good news to me. 

[rumbling_caddy]

Oh yes it's good news.  Maybe typo corrections or I typed too fast, lol

[ORCoaster]

Maybe he is  because he wanted his car to blow bubbles?