Cylinder Head Loosing Pressure Problem

July 26, 2011

Hi,

I had an overheating problem with my 2001 Hilux 2.4TD pickup, changed the radiator and still had problems, took it to a local garage and got told the head gasket needs replacing. As that was done they noticed that the cylinder head was cracked. This got replaced also and I bought one off eBay from a seller called bellocat products. The 1st time I purchased just a bare cylinder head, my mechanic fitted it but could not get the valves to fit properly. Mechanic said that they thought it was a factory error. I spoke to the people at bellocat and they replaced it for me with a complete cylinder head for a bit extra. So got the complete cylinder head fitted. Got my truck back but it didn't feel right. I took it back to the garage they have done some diagnostic tests and found that the 2 of the valves are loosing pressure.

Has anyone ever come across this problem before, is it the cylinder heads that are factory faulty or is it something else like the quality of the valves?!!! Has anyone ever purchased from bellocat before and had any problems or not?

Thanks in advance

S

July 26, 2011

all i can say really is that personally i wouldnt buy something like that from eBay,

i have heard of varying quality's on heads purchased from eBay, as there usually imported by the 10 from china and the like

only place i would recomend would be roughtrax they sell the same kinda heads but as they have premises there more interested in the quality maybe?

July 27, 2011

I have used roughtrax before for other purchases, never had any problems with them.

Thanx for the advice

July 27, 2011

Before fitting any cylinder head whether it be a replacement or after repair a simple paraffin test is essential. All that time and money wasted for the price of a litre of paraffin or white spirit.

Makes me doubt some mechanics abilities now-a-days.

July 27, 2011

Before fitting any cylinder head whether it be a replacement or after repair a simple paraffin test is essential. All that time and money wasted for the price of a litre of paraffin or white spirit.
Makes me doubt some mechanics abilities now-a-days.

What is a paraffin test and what does it determine? :unsure:

Thanx

July 27, 2011

The test simply involves pouring paraffin down each port with it coresponding valves closed - leave for 15 minutes. If the valve is leaking then stains will appear in the combustion area or leak out via the valve stem oil seals. On high performance engines or critical engines such as aircraft, etc, they usally leave it to sit for 12 hours just to be certain.

This method of testing has been around for over 150 years so it ain't a new idea - it was first used on steam engines.:)

July 27, 2011

The test simply involves pouring paraffin down each port with it coresponding valves closed - leave for 15 minutes. If the valve is leaking then stains will appear in the combustion area or leak out via the valve stem oil seals. On high performance engines or critical engines such as aircraft, etc, they usally leave it to sit for 12 hours just to be certain.
This method of testing has been around for over 150 years so it ain't a new idea - it was first used on steam engines.:)

Great thanks for the info, will ask my mechanic if they have done this and if not get them to do it. So if the valve is leaking does this mean that it is just a problem with the valves?

July 28, 2011

Update:

Got a new head from roughtrax, my mechanic has advised me that the valve clearance is too small.

The inlet is measuring 0.15 when it should be 0.20 - 0.30 for the inlet valves and 0.30 when should be 0.40-0.50 on exhaust valves. He has done the paraffin test on the new head and everything is fine apart from this problem with the valve clearance.

Can anyone assist and advise why this is the case, or what we should do? First thing tomorrow i'll be on the phone to roughtrax to get some advice from them also but i know they are not mechanics themselves.

ANY help would be greatly received.

July 28, 2011

Update:
Got a new head from roughtrax, my mechanic has advised me that the valve clearance is too small.
The inlet is measuring 0.15 when it should be 0.20 - 0.30 for the inlet valves and 0.30 when should be 0.40-0.50 on exhaust valves. He has done the paraffin test on the new head and everything is fine apart from this problem with the valve clearance.
Can anyone assist and advise why this is the case, or what we should do? First thing tomorrow i'll be on the phone to roughtrax to get some advice from them also but i know they are not mechanics themselves.
ANY help would be greatly received.

in my experience there very helpful, ask for Barry the owner, he will see you right

they fo seem tight tho

July 28, 2011

Thanx, i'm sure they will help, they have before. Not sure what the problem could be though. I was under the assumption that all the clearances should be the same! :unsure:

July 28, 2011

Thanx, i'm sure they will help, they have before. Not sure what the problem could be though. I was under the assumption that all the clearances should be the same!

even for allowing bedding in or what ever

August 3, 2011

So we sent the head back to roughtrax and it has been tested and falls within the right measurements. The head from them will arrive back to me 2morow. Barry and jack have been extremely helpful. It only leaves me to think its the mechanic!!

Has anybody got any ideas as to why the mechanic is not getting the right measurements? Does anybody know what the tool is called, thinking of getting my own tool!!!

:help:

August 3, 2011

The special tool for checking valve clearance is a set of feeler gauges - just make sure you get a metric set.

August 11, 2011

Just wanted to thank everyone for their help. My truck is now fixed using the cylinder head from Rough Trax, and definitely sounds and feels like it should.

Also i just wanted to mention to everybody DO NOT buy from Bellocat Products. They advertise as OE quality but it is nowhere near quality and after seeing the cylinder head from Rough Trax the difference is EXTREMELY obvious I have seen other posts on another forums for Toyota Estima mentioning the problems they have had with this company as also mentioning not to buy from them ( wish i had seen this before i purchased :jawdrop: !!! ) Just in the process of trying to get my money back.