Spark Plug Issue

Hi Guys,

I just started undoing all the spark plugs on my RB30 Patrol(dual fuel, carby).

First four spark plugs looked ok with some signs of running too lean(kinda thing whitish residue on the spark plug tips).

Fifth one is as in the below pictures.
I'm not sure what the red stuff is. It doesn't exactly look like rust.
Even after giving it a good wire brush(manual) red residue is still there, very much stuck to the tips.

ATM, I'm trying to undo the sixth spark plug which turned out to be extremely tight.
So, I'm guessing it has something to do with that red stuff.
I just sprayed some WD40 and leaving it for couple of hours before I undo the rest of it. It's
way too tight for comfort.

There are signs of slow water loss in the radiator, but I need to confirm it.
I'm not sure whether cylinder 5 and 6 has water leaking into it. But, that is a possibility.
There is no oil in the coolant or vice versa.
But, there is a milky buildup under the rocker cover oil cap, but it's not unusual as I've only been doing short errands and the engine hasn't been getting much of a chance to warm up.

Any ideas about that red stuff on the spark plug?

Spark plug comes out pretty good with resistance test(about 4000 ohm)

Just don't do what I did and snap number 6 off :(

Don't know what the red stuff is or what has caused it but my mechanic said his head machinist said that usually when number 6 won't come out its normally caused from a cracked head.

Hope this isn't the case for you..... good luck

Maybe try a product called Loctite Freeze and Release before trying again

http://www.loctite.com.au/3320_AUE_H...=8802649931777

hate to say it mate but i strongly suggest doing a comp test while hot and a tk test, looks like rust which means coolant is getting into the cylinder, been there a few times myself, my tb42e went 3 times in the same spot due to corrosion until i welded the passages in the head and epoxied the block passages shutAttachment 72429Attachment 72430

oh and this would go a long way to your tuning issues, low power and poor economy

Quote:

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Originally Posted by billyj

hate to say it mate but i strongly suggest doing a comp test while hot and a tk test, looks like rust which means coolant is getting into the cylinder, been there a few times myself, my tb42e went 3 times in the same spot due to corrosion until i welded the passages in the head and epoxied the block passages shutAttachment 72429Attachment 72430

oh and this would go a long way to your tuning issues, low power and poor economy

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What is a tk test mate?

How is possible to epoxy the block coolant passage(the leaking spot one?) shut?
Wouldn't you create temperature issue on the block by doing that?

First thing tomorrow I'll be doing the compression test.

I just marked the water level in the coolant overflow reservoir & topped the radiator and drove for 10km.
I'll check to see whether the water level has gone down in the radiator and no change in the coolant overflow tank.

Thanx

Quote:

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Originally Posted by NissanGQ4.2

Just don't do what I did and snap number 6 off :(

Don't know what the red stuff is or what has caused it but my mechanic said his head machinist said that usually when number 6 won't come out its normally caused from a cracked head.

Hope this isn't the case for you..... good luck

Maybe try a product called Loctite Freeze and Release before trying again

http://www.loctite.com.au/3320_AUE_H...=8802649931777

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I think it is the head.

The number 6 spark plug came out after I sprayed some WD40 and left it for half hour and removed it.
I couldn't see any of the red stuff on the spark plug, but it's possible the WD40 broke it down as it's covered with WD40.
Plug is in good nick other than tightness, but it's not tight anymore.
The reason for tightness is carbon buildup(I think, but I can be wrong about that).
I couldn't see anything clearly on the thread that caused the plug to be tight, but some thing black stuff.
Most likely WD40 broke down the stuff.

I has been five years or so since the last cyinder head job, so I reckon it's about time.

I think I'll pull the head out either way, 'cos the last head job was half hearted one due to time
issues. This time I'll do a good job.

Had the dreaded milky stuff under the oil filler cap on the maverick and the GQ , both had head gasket issues and both were leaking .
Seen a nifty trick for finding out for sure and that was remove the radiator cap and put a condom over the filler neck and start the car and see if the condom starts to inflate .

tk test is tests the radiator for any exhaust gases with engine running, welding/epoxing the passages was easy enough and caused no temp issues as there was already plenty of flow through the area

http://wbtools.com.au/products/autom...leak-detector/

this is a tk tester, basically you put some fluid into the tester and with the radiator leve down just enough that it wont suck coolant you pump the top so it draws air from inside the radiator, any presence of combustion gases and the blue fluid will turn yellow, you can get a kit like above at repco, supercheap etc

Quote:

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Originally Posted by billyj

tk test is tests the radiator for any exhaust gases with engine running, welding/epoxing the passages was easy enough and caused no temp issues as there was already plenty of flow through the area

http://wbtools.com.au/products/autom...leak-detector/

this is a tk tester, basically you put some fluid into the tester and with the radiator leve down just enough that it wont suck coolant you pump the top so it draws air from inside the radiator, any presence of combustion gases and the blue fluid will turn yellow, you can get a kit like above at repco, supercheap etc

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Ok, cool thanx. I have a home made setup(with a CO detector/alarm) with the radiator burp gadget, which I can use to do a combustion gas leak test from the radiator. The test came out good late last year.
I think the head is stuffed. It looks like coolant is leaking into the cylinder 5 & 6.
I'll find out tomorrow.

Thanx

do a proper test with a tk tester or get a mechanic to do it( only takes about 20 mins) and do a compression test hot, if theres even a slight issue with the head or gasket you will know, and its much better to know before diving into ripping a head off

Quote:

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Originally Posted by billyj

do a proper test with a tk tester or get a mechanic to do it( only takes about 20 mins) and do a compression test hot, if theres even a slight issue with the head or gasket you will know, and its much better to know before diving into ripping a head off

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Thanx mate. I'm yet to do the combustion gas leak test. I'll get it done tomorrow.

I did the compression test today. I opened below thread with the results.

Compression Test Results