Carbon on intake valves

[Torchred96]

As you probably know, I have been doing the injectors and secondary throttle blades mod and a few other things while i'm in there.....I was looking into the intake ports on the heads to make sure I didn't drop anything into them, I noticed a pretty good amount of carbon on the valves..

Of course, I am tempted to do something about it, but what can I do? Is there any known solvent for carbon buildup? Hate to ignore it. Recall I have a bunch of miles 133k. The engine doesn't smoke...(oh and it doesn't like alcohol or drugs either).

thanks

[1990 415]

Drive it like it was meant to be driven and blow the carbon off the valves.

[Torchred96]

I'll certainly do that, but will it actually blow the carbon off? or is that a myth?

[batchman]

I think the old saying really applies to carbon in the combustion chamber, which was common on lazily run carb'ed cars. For today's EFI intake tracts you should look into Seafoam or similar. Haven't tried the likes of that in the ZR-1 yet though...

Best,
- Jeff

[1990 415]

I'll certainly do that, but will it actually blow the carbon off? or is that a myth?

It is no myth. LT5s need to see 7000 rpm on a regular basis.

[Ccmano]

If you drive with the secondaries turned off (at the valet switch) regularly, this is what happens. Even Haibeck recommends you leave the switch on for full power at all times. That way you'll get into your secondaries from time to time and help keep them clean. In extreme cases a carbon accumulation like this it causes hard starting, rough idle, knocking and dieseling because the carbon absorbs the fuel. I've seen cars (not ZR-1's) that literally would not start because of this.

As for cleaning there's Seafoam,Techron and BG44K. These can either be put into the fuel or introduced directly to the intake. We used to do this on Benz's that had this issue with Techron. It's tricky, I don't recommend it unless you know what your doing. You run the risk of hydostatic lock if you use too much too quickly. There are systems on the market that allow shops to do this eliminating the risk. Many shops offer this service now.

Your best bet is to run a few tank fulls with high concentration Seafoam, Techron or BG44K (read the directions) and do a bunch of high rpm runs occasionally. I like the BG44K the best.

H
:cheers:

[Torchred96]

Ccmano and Jeff, I read a little about the bg44k and seafoam b4 I posted but I was looking for personal recommendations for the Z and what some of our experts thought and so thank you for your thoughts.

I'm gonna try one of the products and see how it works out. I don't experience any of these symptoms (" hard starting, rough idle, knocking and dieseling") but just looking at those valves doesn't make me warm and fuzzy.

Thanks again to all who replied.

[tomtom72]

:o Okay, I'll fess up! After my recent bout with spark knock I was fairly panicked and bummed out. The cause turned out to be loose spark plugs.:o

But. In an effort to chase down the reason for the knock I ran down all the various codes that could have been logged in by the ECM. No, I had no DTC's even in history. Sooo, I bought about six cans of seafoam. I added one can to a tank full six times, but skipping one tank each time. Okay not exactly a whole 18 gallons but you get the idea. Okay, so I find the loose plugs and after I fix that ( jez I can be so dumb sometimes ) I noticed the motor sounds different. It seems to be breathing easier? Or smoother? I don't know it may be my wishful thinking? It just seems like she's her old self again, and nothing broke from using the seafoam.

I had an issue with dumping it in the brake booster hose that's why I did the six tank fulls. Go to their web site and read up on all the instructions and think about which cylinders the booster hose is near. That was my sticking point on not doing it that way. How do the front cylinders get an even dose???? Gas tank takes longer for sure, but everybody gets a little bit!

:cheers:
Tom

[FU]

but everybody gets a little bit!

:cheers:
Tom

We are still talking about the LT5 here ?

[scottfab]

Drive it like it was meant to be driven and blow the carbon off the valves.

nuff said.;)

[Paul Workman]

Coolant injection does wonders too...But I don't recommend it!:sign10:

One of the advantages of running w/o SPTs is the valves get cleaned ALL the time, except at idle; don't idle the LT5...they're made to run fast, and will load up big time when idled for many or prolonged periods. Bury the tach whenever possible, and as Dave Mclellan said: "(the LT5) will thank you for it!"

P.

[tomtom72]

We are still talking about the LT5 here ?

:dancing....... I was , what were you thinking Frank? :mrgreen:


:hello:

[Torchred96]

Good to know another benefit of removing the spt's. I just learned another acronym too!

[gbrtng]

Take a look: http://www.toptiergas.com/deposit_control.html

and: http://www.toptiergas.com/retailers.html

Buy quality fuel instead of futzing around with additives ...

[VetteMed]

Good to know another benefit of removing the spt's. I just learned another acronym too!

Umm, wouldn't it be STP?

Secondary
Throttle
Plates

[Torchred96]

Umm,

Haibeck Automotive Technology



Verifying the Operation of the Secondary Port Throttles With the Plenum in Place

I'm not gonna tell him he's wrong...You do it :)

[VetteMed]

Well I guess that makes sense too. Most of us 'round here call 'em throttle plates. Carry On! :)

Umm,

Haibeck Automotive Technology


Verifying the Operation of the Secondary Port Throttles With the Plenum in Place

I'm not gonna tell him he's wrong...You do it :)

[Torchred96]

Thanks for the pass. I'll pass the word on to Mr. Haibeck that if he ever comes round these parts, make sure he gets them acronyms right, 440ci or not!

Carry on Sir.

[tomtom72]

Not to slice and dice words.....but in the FSM yes the system is called the secondary port throttle system, and the butterflies are called the secondary port throttle plates......soooo, if you remove the secondary port throttle butterfly plates and all the associated hardware you are removing the secondary port throttle system.:neutral:

I'm just saying...., ya know?:mrgreen:

:cheers:
Tom

[VetteMed]

OK, OK, I'll go crawl back into my cave.

[Torchred96]

nah, it's all in fun.. :handshak: