RangeRovers.net Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hey guys..I need some advice.I have a 1999 range rover p38 with a 4.0.I cant get rid of this danm cly 7 misfire light..new coil pack...new plugs..new wires..switched coil amd wires to see if problem would move amd it doesnt..Took off intake and moved injector to a different clyinder and problem stayed on clyinder 7..150 psi compresion on all clyinders.I notice im losing a bit of coolant..im talking like a cup for every 8 hours driving...Could this be my issue??Car runs terrible with engine light flashing every 5 min or so.. Im hunched!Thx for any help or advice..
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
114 Posts
Whatwas the plug like when you took it out? Did it look bright and shiny or dull and a bit Carbone’s up? If the former you have water or coolant getting into the cylinder and “steam cleaning” it, if the latter you might be able to rule out a head gasket (never say never of course).

Number 7 is against a head to block water passage so it is possible for the gasket to go internally and let coolant into the cylinder. If that is the case, then no a big problem to fix. If that is where your problem is, you would expect the cooling system to be pressurizing somewhat though. Is it?
 

·
Premium Member
1995-2002 Range Rover P38A
Joined
·
243 Posts
Let's say all of the parts you replaced are good from the factory (I've seen faulty brand new non oem coil packs before). One thing that comes to mind is the fuel injector. Sounds like it may be clogged up. A fuel pressure drop test would confirm this. Another way would be to move the injector to another cylinder to see if it moves.
 

·
Registered
Joined
·
162 Posts
Helpful if you could compare plugs and possibly post photos here-my thinking as above if coolant in the cylinder.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #7
Whatwas the plug like when you took it out? Did it look bright and shiny or dull and a bit Carbone’s up? If the former you have water or coolant getting into the cylinder and “steam cleaning” it, if the latter you might be able to rule out a head gasket (never say never of course).

Number 7 is against a head to block water passage so it is possible for the gasket to go internally and let coolant into the cylinder. If that is the case, then no a big problem to fix. If that is where your problem is, you would expect the cooling system to be pressurizing somewhat though. Is it?
Thanks for the advice..The plug was black.all others light brown.Yes.it has a very small amount of pressure.When i take cap off i get a tiny amount of air coming out..The black plug confirms that its really misfiring number 7 in my opinion.Not sure why.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Whatwas the plug like when you took it out? Did it look bright and shiny or
Thanks for the advice..The plug was black.all others light brown.Yes.it has a very small amount of pressure.When i take cap off i get a tiny amount of air coming out..The black plug confirms that its really misfiring number 7 in my opinion.Not sure why.
Whatwas the plug like when you took it out? Did it look bright and shiny or dull and a bit Carbone’s up? If the former you have water or coolant getting into the cylinder and “steam cleaning” it, if the latter you might be able to rule out a head gasket (never say never of course).

Number 7 is against a head to block water passage so it is possible for the gasket to go internally and let coolant into the cylinder. If that is the case, then no a big problem to fix. If that is where your problem is, you would expect the cooling system to be pressurizing somewhat though. Is it?
Thanks a bunch for the advice..I took head off and found a broken exhaust valve spring..Weird i still had good compression no?
284013
 

·
Registered
1995-2002 Range Rover P38A
Joined
·
114 Posts
If the plug is black then it is unlikely to be a coolant/head gasket issue.

You can get a globe and some wire to test if the injector is getting a signal. If the wiring is damaged then the injector may not be delivering fuel. In addition I have seen badly corroded fuel rails, with internal rust which might restrict the flow.

A black sooty spark plug suggests a lack of airflow or over fuelling. Perhaps the issue might be the reverse with the wiring, where it is getting a positive feed all the time and allowing full to over feed the cylinder.

Someone on here will be better placed than me to discuss this particular thought.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #10
If the plug is black then it is unlikely to be a coolant/head gasket issue.

You can get a globe and some wire to test if the injector is getting a signal. If the wiring is damaged then the injector may not be delivering fuel. In addition I have seen badly corroded fuel rails, with internal rust which might restrict the flow.

A black sooty spark plug suggests a lack of airflow or over fuelling. Perhaps the issue might be the reverse with the wiring, where it is getting a positive feed all the time and allowing full to over feed the cylinder.

Someone on here will be better placed than me to discuss this particular thought.
Thx for the help..Turned out to be a broken exhaust valve spring.Weird it had good compression no?
 

Attachments

·
Registered
1995-2002 Range Rover P38A
Joined
·
450 Posts
did you find any fissures or cracks in the head gasket to explain the coolant loss
 

·
Registered
Joined
·
5 Posts
Discussion Starter #12
No i didnt..but im sure i have an issue as in the valve cover was thick with white paste.going to pull other head off.The gasket on the one i just took off looked perfect
 
1 - 12 of 12 Posts
Top