#46: Re: Here is My Spark Plug Reading Condition-What do you see? Author: kandlbarrett, Location: SwindonPosted: Sun Jan 25, 2015 10:48 pm ---- Seal product won't work if the leak is compression between two cylinders - rare but does happen.
You seem to assume I am recommending compression test to test head gasket. I am more inclined to think you have low compression doe to bore and ring wear; that is why I say compression test it. Very cheap to do (Simple DIY) and rules out wasting money on other things if compression is down.
Head gasket tests are sniff, compression and leak down. I have done them all but I have only done leak down only on large (8 litre plus) industrial diesels. If there are more tests please educate me and the others here. I am alway open to new information or knowledge. What test have you done and why choose that?
In you previous post you stated that you had been recommended a valve cleaning product to clean the combustion chambers. As you haven't discounted that I assume you are considering it. If the head gasket was done 6 months ago it would be a very sick engine that was clogged up already.
#47: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 2:22 am ---- When I changed the gasket, I skimmed the cylinder head which is something I regret that I have done! Skimming the head always reduce performance. And whether someone tell you it is just small or big amount that has been cut off, it will anyway reduce performance.
The spark plugs carbonating issue started few months before the head gasket job. But yes I agree that you may need some valves cleaner after the head gasket job, and this can be a part of the current smoking problem.
My problem with the compression test is that not too many folks around perform it on 206. My mechanic who has been servicing my car since 2000 is saying that I don't have to worry now about the piston rings. And the current leak is still acceptable.
This puts me back to start searching for what is causing the over fueling in my car. Lambada, MAP, TPS,...etc. I really hate searching around those sensors. Actually this car injection calculating sensors and parts (inclusive the ECU) are not reliable at all.
#48: Re: Here is My Spark Plug Reading Condition-What do you see? Author: kandlbarrett, Location: SwindonPosted: Mon Jan 26, 2015 8:01 am ---- If you won't do a compression test to just rule it out I offer no more advice. Good luck.
Skimming a head should improve performance unless you have really crap fuel that is outside the ECU adjusting for.
Buy the tools and compression test yourself. You worked as an Engineer in a service department so know how to do it and how easy it is.
Good luck - keep guessing.
#49: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 10:52 am ----
kandlbarrett wrote:
Skimming a head should improve performance unless you have really crap fuel that is outside the ECU adjusting for.
No Kandlbarrett.
It sounds that you are talking for the perspective of tuning and increasing the compression ratio while you don't see it from the other side. Here are the facts:
Result of polishing a cylinderhead is generally:
A few BHP + in most high revs.
You will loose some in low revs.
Reason: a good combustion needs a minimum in turbulence to burn good and completely.
Explanation of what will happen after this:
High speed (= high rev) gasmixture will burn good because it is 'slammed' into the combustion chamber and thus mixture will be fine. You win BHP because the intake part of cylinderhead offers less resistance and more air can enter.
Low speed revs: you loose BHP because the gas/air has no high speed (low revs) and so there's not enough speed/turbulence to create ideal circumstances for the mixture to burn perfect.
Conclusion: this is a typical 'high performance' tuning, only of use for engines that run only in the highest revs at full load. At low revs or in daily use this is money thrown away. It will be much better to get a new cylinder head.
Skimming the cylinderhead: you're lucky to have a knocksensor. Because the risk for detonation increases (compression is higher). Pay very well attention to
- valvetiming as the distance from the camshaftpignonwheel -> crankshaftpignongwheel will decrease.
- distance valve - piston
That's why using high compression pistons is highly recommended in tuned engines over the cylinder head polishing. The result will be better (higher compression) and the HC pistons leave some space for the valves.
Thanks anyway for your follow up.
#50: Re: Here is My Spark Plug Reading Condition-What do you see? Author: gazza82, Location: South BucksPosted: Mon Jan 26, 2015 11:10 am ---- Uh? What are you talking about?
The suggestion to "skim" the head is nothing about performance .. it's to make sure it is perfectly flat!
And the compression test is to check you don't have a rings issue .. if everything is as it should be you will have no difference across the four readings .. if you have you need the engine out. Look up "leak-down" test as well ... that will show how much compression is being lost through bad rings, worn bores or dodgy valves.
Why is your "mechanic" so against checking? Is it that he knows you have an engine issue but this way he can make more money out of you?
Oh and skimming a cylinder head IS a performance tweak ... it doesn't make a lot of HP, but it is part of a tuned engine to increase compression ratio.
#51: Re: Here is My Spark Plug Reading Condition-What do you see? Author: kandlbarrett, Location: SwindonPosted: Mon Jan 26, 2015 4:03 pm ---- I have never known anyone complain that they had their head skimmed when having a gasket renewed before. I am astonished.
I have been tuning cars since the Leylamd 'A' series, through Ford Crossflow and Pinto, Escort turbo then Fiat and Alfa twin cams and what you say is true but nothing like enough to mean any one wouldn't skim their head if needed on gasket renewal or just to be certain it is perfectly flat. Also with high mileage engine and Alloy head it would be very unusual not to have some surface pitting that will be stress points for the gasket and a skim will remove or make these much smaller.
And who said anything about polishing? Not me!
A compression test may prove nothing wrong but is a step that I feel is essential.
You are an ex Service Engineer I don't understand why you aren't doing it yourself. Last edited by kandlbarrett on Mon Jan 26, 2015 4:14 pm; edited 1 time in total
#52: Re: Here is My Spark Plug Reading Condition-What do you see? Author: kandlbarrett, Location: SwindonPosted: Mon Jan 26, 2015 4:10 pm ---- One last one. You still haven't described which of the many different ways you used to test the head gasket.
End for me.
#53: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 4:22 pm ----
kandlbarrett wrote:
I have never known anyone complain that they had their head skimmed when having a gasket renewed before. I am astonished.
Actually, I have seen most of overheating issues ended with head gasket replace + cylinder head skim! May be you have never known anyone experienced a bad overheating before.
#54: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 4:26 pm ----
gazza82 wrote:
Uh? What are you talking about?
The suggestion to "skim" the head is nothing about performance .. it's to make sure it is perfectly flat!
Agree. But sometimes it is better to get another head rather than skimming it.
Kandlbarrett suggested that this would increase performance, but I don't see it like this for daily use cars.
#55: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 4:29 pm ----
kandlbarrett wrote:
A compression test may prove nothing wrong but is a step that I feel is essential.
I don't have the tool. Plus I have been putting my hand in this 206 for 14 years, you can say I got bored from it
#56: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 4:30 pm ----
kandlbarrett wrote:
One last one. You still haven't described which of the many different ways you used to test the head gasket.
You didn't tell me why I should bother checking the head gasket?!
Anyway I used to do the pressure test for the cooling system.
#57: Re: Here is My Spark Plug Reading Condition-What do you see? Author: kandlbarrett, Location: SwindonPosted: Mon Jan 26, 2015 4:53 pm ---- You state you were a service engineer but are now using a mechanic! I have never seen a good mechanic, even after leaving the trade not have a basic tool kit and DIY their own car. Especially on old car.
You can remove plugs to take photos but won't or can't do a compression test?
You have fouled plugs and don't know if the car is running rich or lean!
At one point you seem surprised by my suggestion that a head gasket can fail without water leaking then come back asking me if I have heard of head gasket failure modes?
I ask anyone here if they have heard of a first skim for gasket renewal to cause over heat?
You have said you know the head gasket it isn't a problem. I asked how you knew and you said there are more ways to check than compression test and you know head is good but won't say how you know that.
You have shown photos of two plugs but not, as promised, of the other two. Why not?
In one post you state you are burning oil then later change your mind. In another you complain of black exhaust both suggest worn rings.
The tool is very cheap (less than £15 on eBay) buy one and take photos of the results.
I am frustrated and, after reading your posts from beginning to end, I can only conclude that you are all theory and have very little or no practical application.
#58: Re: Here is My Spark Plug Reading Condition-What do you see? Author: kandlbarrett, Location: SwindonPosted: Mon Jan 26, 2015 4:55 pm ---- Pressure test for cooling system doesn't prove head gasket. What a joke.
#59: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 5:15 pm ----
kandlbarrett wrote:
I am frustrated and, after reading your posts from beginning to end, I can only conclude that you are all theory and have very little or no practical application.
So you are here to assess everyone's skills based on your opinion about his posts? And claim that you are the chief of knowledge?
You should help or stay off! If I know how to solve this, I would have never posted anything here. But the forum will not look helpful with such a conversation. Last edited by hamed206 on Mon Jan 26, 2015 5:45 pm; edited 3 times in total
#60: Re: Here is My Spark Plug Reading Condition-What do you see? Author: hamed206, Location: EgyptPosted: Mon Jan 26, 2015 5:16 pm ----
kandlbarrett wrote:
Pressure test for cooling system doesn't prove head gasket. What a joke.
Yes, the joke was your question not my answer, the assumption of head gasket has nothing to do with my problem!
And you came up with your theory: skimming cyl head improves performance!! And failed to discuss this scientifically. Last edited by hamed206 on Mon Jan 26, 2015 5:51 pm; edited 3 times in total
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