Fuel Injector O-Rings - Lube or No?

[AJB0009]

Quick question:
When replacing fuel injector O-rings, do you put anything on them?
I've read of some coating with fresh engine oil before installing.

 

[Kestas]

Never install them dry. Oil, grease, vaseline... anything but dry.

 

[GMBoy]

Service manuals say fresh engine oil. Like said above - never dry.

 

[Kurtatron]

I replaced those on my 91 Toyota a few years ago. The OEM workshop manual said to dip them in gasoline before installing.

 

[GoldDot40]

X2 on motor oil...or ATF. Never dry fit them.

 

[The Critic]

Never dry. I use tune-up grease or silicone brake slide pin grease.

 

[demarpaint]

IIRC I believe it was @Trav that told me to use Super Lube grease when I did mine. It worked great.

 

[Trav]

Yes, it works well.

 

[clinebarger]

I use Red TransJel as I always have it on my work bench, But like said.....Never dry.

 

[slacktide_bitog]

Yes you have to lube them with something!

I put some oil around the O-rings when I had to replace my injectors. Yeah it smoked for a few seconds after, but it's ok

 

[Trav]

As a side note. The best thing I found to remove the old ones is WD40, spray some down where the O ring sits, a little twist it pops right out.
For some reason WD is the possibly the best rubber lube I have used but it short lived.

 

[AutoMechanic]

I’d say silicone spray would work or a grease of some type.

 

[Trav]

You dont want to start spraying silicone near any opening that leads to the combustion chambers eg throttle body, injector openings, vacuum ports, etc. It can kill the cat.

 

[mk378]

Silicone may also have a reaction with the rubber which is made to withstand gas / oil. So definitely use an oil based material.

 

[AutoMechanic]

You dont want to start spraying silicone near any opening that leads to the combustion chambers eg throttle body, injector openings, vacuum ports, etc. It can kill the cat.

Oh I was unaware of that. I haven’t done many injectors in my time as a mechanic last time I did was rebuilding the engine in my friends Subaru I think I used grease on them.

 

[mehullica]

Gasoline

 

[brianl703]

Never dry. I use tune-up grease or silicone brake slide pin grease.

I heard years ago that using silicone grease can result in a plugged injector because it doesn't dissolve in gasoline. I always use motor oil.

 

[The Critic]

I heard years ago that using silicone grease can result in a plugged injector because it doesn't dissolve in gasoline. I always use motor oil.

Just checked the service info for a few cars. You are correct - they all recommend motor oil or gas.

 

[Lubener]

Motor oil no silicon based lubricants.

 

[daves66nova]

!@#$%, I installed 6 of them ,DRY, on my son's car. I t hasn't been fired up yet, if that matters. 91 Cressida.