Does anyone know how or what could cause valves to turn blue?
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Valves are Blue
- Thread starter dlynes
- Start date
Heat
what color should they be and how bad is it to have blue valves?
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Better to have "blue vales" than blue balls, I would say. Seriously, I would think that would indicate you are running lean. Are you boosted?
stainless steel (i would assume the valves are made of ss) heat treats to blue at around 1000F. now under normal operations, the exhaust gas will be considerably higher than 1000F (exhaust outlet temperatures can range between 800F-1500F, and flame temperature is even hotter), but the valves are exposed to these temperatures for a very short time.
when ss is heat treated, it becomes harder and more brittle. only in the most extreme cases would i think a valve could break from its normal opening and closing operation, even if it is heat treated.
i would think that they turned blue because of running lean.
can you list what modifications you have done that could possibly cause you to run lean?
when ss is heat treated, it becomes harder and more brittle. only in the most extreme cases would i think a valve could break from its normal opening and closing operation, even if it is heat treated.
i would think that they turned blue because of running lean.
can you list what modifications you have done that could possibly cause you to run lean?
thanks for your in depth reply and not someones lack of sexual forfillment.
I do not have any mods to the car minus wheels, suspension, intake box and exhaust.
mechanic and the machine shop both recommended replacing all valves at a cost of $675
my idle is been fluctuating for the past year, idling anywhere from 250 to 1700 and sometimes even shutting off. I did hook car up to a stap on machine and determined engine was running lean.
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if the car is basically stock engine wise, there are a few things you can check.
testing/check/replace o2 sensors. (would be my guess)
fuel pressure. (possible)
send your injectors out for cleaning and benchmarking. (probably not)
those are really the only things i can think of.
as for if the valves need to be replaced: i don't think any one can know the answer. if they are severely heat treated, they can be brittle enough to break under normal operation, which, if that happened, would cause catastrophic engine failure (a la snapping a valve at the stem/dropping a valve, shattering a valve, etc) also, you may want to check the remainder of the valvetrain. if the valves were exposed to such elevated heat levels, i would assume the remainder of the head also was exposed.
i am speaking from a purely theoretical point of view, as my experience is limited, so i would wait on a few more individuals to chime in and give their opinions/advice.
testing/check/replace o2 sensors. (would be my guess)
fuel pressure. (possible)
send your injectors out for cleaning and benchmarking. (probably not)
those are really the only things i can think of.
as for if the valves need to be replaced: i don't think any one can know the answer. if they are severely heat treated, they can be brittle enough to break under normal operation, which, if that happened, would cause catastrophic engine failure (a la snapping a valve at the stem/dropping a valve, shattering a valve, etc) also, you may want to check the remainder of the valvetrain. if the valves were exposed to such elevated heat levels, i would assume the remainder of the head also was exposed.
i am speaking from a purely theoretical point of view, as my experience is limited, so i would wait on a few more individuals to chime in and give their opinions/advice.
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Blue paint can cause almost anyhing to turn blue.
but seriously , how new are they that you can see the color , usually they are black from carbon by the time you take them out.
but seriously , how new are they that you can see the color , usually they are black from carbon by the time you take them out.
OK, I gotta ask. Is this the same shop that charged you over $14k on the last 2 visits? Let me be honest and say I think you're being taken advantage of. It sounds outrageous and it simply doesn't pass the sniff test. It sounds like you went in there because of a bad idle and now they're saying your valves are blue...is this right? Did you verify their findings? Are they suggesting you replace all the valves, or just all the exhaust valves? Please expand on the scanner diagnosis that indicated a lean mix. Was the MIL lit?
Agreed. How do you know the valves are blue unless you have the head off or are using a bore scope? Is some technician just telling you this? This all sounds a little strange to me.
OP, you need to grow a sense of humor too. You know what they say about people that can't take a joke.
The engine and heads have both been taken apart and the
As far as taking a joke, I love a good joke but there is a time and place for everything. Over my years of experience on this forum, I get a lot of great, info but unforunatly a lot of jack asses rambling on about nothing about the topics asked. I am not saying that is you but by reading my threads and others I see a lot of stuff thats irrelavant and unneccessary
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Understood. That's why they call them "Post Whores". Sorry you are having such a difficult time. Hope things work out for you where you can get the car back and in proper working order. Good luck---
Thank you! I really appreciate it
I am glad you clarified that a little. You kinda fell victim to the post whores on your own by not providing any real information about your problem. You and I both know there is alot more to this than you have let on here on this forum. For now, I'll leave that to your discretion.:smile:
If you feel the valves need to be replaced, you may wish to consider these. They are the 36mm size from your engine type (3.2L). They are much less expensive than stock ($197.84 for the full set).
http://www.scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/valves/
As far as the lean condition, typically, if the engine starts to see lean conditions, to the point where you're getting very high cylinder temps, I'd expect there to be detonation. Detonation from the aluminum pistons and aluminum head will form on the plug and valves as a very fine light grey 800 grit sand paper looking finish. he exception could be if the car running very high temps but very low cylinder pressure (such as only during idle conditions where there is no load).
As far as the reported lean condition, I assume they used a OBD2 scanner. What do you consider lean (under load or just idling?) Is one cylinder bank different than the other? If so, I would inspect your cam shaft timing, especially if you just had a recent service. If they are the same, rule out why the car is running lean by checking fuel pressure and injectors.
take care,
-- Chris
http://www.scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/valves/
As far as the lean condition, typically, if the engine starts to see lean conditions, to the point where you're getting very high cylinder temps, I'd expect there to be detonation. Detonation from the aluminum pistons and aluminum head will form on the plug and valves as a very fine light grey 800 grit sand paper looking finish. he exception could be if the car running very high temps but very low cylinder pressure (such as only during idle conditions where there is no load).
As far as the reported lean condition, I assume they used a OBD2 scanner. What do you consider lean (under load or just idling?) Is one cylinder bank different than the other? If so, I would inspect your cam shaft timing, especially if you just had a recent service. If they are the same, rule out why the car is running lean by checking fuel pressure and injectors.
take care,
-- Chris
I started this thread asking what could cause blue valves. It was not started to talk about previous threads on my service bills/expenses nor was it to bash anyone.
As stated in my other thread, after the service is finalized and complete, I will post what was done and the expenses. That thread was only started to say that I wish I was fortunate enough to have had the chance to put money into the car for mods/track use instead of service costs.
Just want to clear any confusion.
as always, thanks for the relevant and resourceful information for those that gave it
Since you quoted me, I assume you are responding to me. I stated what I did because, as I am sure you noticed, many folks are refering to your plight with other posts in mind. You did the same thing in the other posts as you did this one, you didn't give all the information. This led to a free-for-all of misinformation and post-whores throwing their two cents in. There were a few that actually tried to be constructive but it seems they also noticed that there was not quite enough info as well. If you want peoples insight without wasting their time, then give them all the relevant info. If you want sympathy, don't make it a question. Not trying to be harsh, just relevant.:smile:
I did not ask for sympathy. I simply asked what could cause blue valves
