random engine knocking

A

aroshan

Well-known member
Nov 10, 2006
51
0
orange county, CA
Hey guy I have a 03 disco with the 4.6 engine. I have 80k miles on it and I had all gaskets replaced under warranty because I fluid leaks. I?ve always use mobile one synth 10-30 on the truck with the K&N long filter. Since I?ve been reading it seems like the long filter is not a good thing. What oil weight should I be using for California cold weather? the knocking sound have come back since the gasket replacements but this time it is louder and stays on when I drive up to around 20mph and then goes away. Sometimes there is not sound at all and everything seems good. Any help would be great

It seems like the 10-30 synth is getting thin to fast. Are the higher the numbers go the thicker the weight?


Thanks again
 
smelly pirelli

smelly pirelli

Well-known member
Dec 26, 2007
185
0
kirkville ,NEW YORK
what is cali cold weather ? how cold , in cold 50degs and lower 5w-30 is what you need , needs to be thin . What grade gas are you using? please tell the truth!! we want to help you !!!!!!!!
 
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aroshan

Well-known member
Nov 10, 2006
51
0
orange county, CA
california cold weather, and the temp is 45-55 degrees out when it starts in the morning, but the sounds also happens when the truck has been driven a few miles and it's warm out so i dont know if the tempature outside is a problem or not. im useing 91 octane gas and it's the truth. i took the truck to the dealer when i first heard the sounds like 10k miles ago and the did $4500 worth of work on all gaskets but now the sound is back.


thanks for any help
 
smelly pirelli

smelly pirelli

Well-known member
Dec 26, 2007
185
0
kirkville ,NEW YORK
aroshan said:
california cold weather, and the temp is 45-55 degrees out when it starts in the morning, but the sounds also happens when the truck has been driven a few miles and it's warm out so i dont know if the tempature outside is a problem or not. im useing 91 octane gas and it's the truth. i took the truck to the dealer when i first heard the sounds like 10k miles ago and the did $4500 worth of work on all gaskets but now the sound is back.


thanks for any help
Click to expand...
try using 93oct my friends 04 wont take anything else , could be timing! but try the high test gas ,run out what you got and fill up 93oct! 1 bottle gummout fule injecter cleaner!
 
Discotec

Discotec

Well-known member
Mar 30, 2006
483
0
Glenwood, N.B. Canada
smelly pirelli said:
try using 93oct my friends 04 wont take anything else , could be timing! but try the high test gas ,run out what you got and fill up 93oct! 1 bottle gummout fule injecter cleaner!
Click to expand...

Correct me if i'm wrong here but don't all Discos require high octane?

Happy New Year to all........ :)
 
G

gearco

Guest
According to my mechanic, there is a problem with the 4.6 oil pumps. They routinely make a ticking sound after startup and then quiet down later. Might put a scope around the pump and see what you hear.
 
A

ausdisco

Guest
your belts and pulleys can tend to make a 'knocking' sound when loose too. (just throwing it in the mix)
 
A

aroshan

Well-known member
Nov 10, 2006
51
0
orange county, CA
During idle and slow acceleration it knocks, it kind of sounds like it is from the fan hitting something but it's not. It’s inside the engine but the sound seems to be timed with the rotation of the fan.
 
KDamericano

KDamericano

Well-known member
Oct 16, 2006
193
0
Denver, CO
With that many misfires, I'd say it's probably due to the gas you're using. I'd start there before throwing parts at it. Fill up with high octane, and see if that makes a difference.
 
ptschram

ptschram

Well-known member
Sep 27, 2004
21,955
49
In the shop doing the Lord's work one broken Rover
www.ptschram.com
KDamericano said:
With that many misfires, I'd say it's probably due to the gas you're using. I'd start there before throwing parts at it. Fill up with high octane, and see if that makes a difference.
Click to expand...

Poor gas would be unlikely to result in misfires as the EMS would merely retard the timing to compensate for the fuel.

Misfires are much more complicated.

At 80K, it's time for plugs and wires first.
 
KDamericano

KDamericano

Well-known member
Oct 16, 2006
193
0
Denver, CO
Last time I ended up with subpar gas I threw about 5 misfire codes. Topped off with premium and the codes went away. I'd also agree that if they have not been done yet, it's time for plugs and wires though. Gas is just an easy place to start.
 
C

ciaops07

Member
Dec 2, 2006
24
0
I would check your plugs and wires if you haven't had them replaced lately. I had a similar problem with my 03 disco on three cyclinders. it ended up being bad wires and plugs at 50,000 miles. I run 87 most of the time with injector cleaner every oil change and have never had a problem with pinging or knocking in 130,000 miles. I had an unrelated knock a few thousand miles ago but it was nothing that a new engine didn't fix. gotta love rovers :banghead:
 
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CoyGlasscock

Guest
Mine is doing the same and has been for the last 6,000 miles (i put 4,000 miles on it in December), I will put a scope on it this week-end and try to pin point it. I am thinking Cataltic Converter. I just replaced wires, plugs and o2 sensors about 5,000 miles ago along with valve cover gaskets and hoses and a new belt. I have done 2 oil changes since it started and it seams to get worse at random. Mine came up with the same codes a while back and I was about 1,000 miles away from home so I drove it anyway. I have been told that driving with misfires for a long time can damage Cataltic Converters.

P.S. Can't get 93 octane in California. I always use 91 when in Cali and use the highest when in other states.
 
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