| Author | Message | ||
     frank berry (Spencer) New Member Username: Spencer Post Number: 1 Registered: 02-2003 |
Not sure if this is a dumb question or not but i bought this 97 with 75k on it -had to replace the intake mani left side and the steering box other than that it's great and did a 3 week 7k trip out west this summer. One thing i can't figure out is the faint knocking sound when you accelerate. I'm thinking this isn't good - i always use premium gas and it isn't that kind of knock -any help would be greatly appreciated-thanks fb | ||
| Kyle Van Tassel (Kyle) Moderator Username: Kyle Post Number: 40 Registered: 11-2002 |
Is it a ping , or a knock ??? If its a ping you might need some better gas. Kyle "Blow me" | ||
| frank berry (Spencer) New Member Username: Spencer Post Number: 2 Registered: 02-2003 |
it's a steady knock as you accelerate | ||
| Kyle Van Tassel (Kyle) Moderator Username: Kyle Post Number: 41 Registered: 11-2002 |
Hmmm , nothing at idle or start up ? I have heard cracked flywheels do that but havnt seen one on a Disco. Perhaps if Trevor is reading he can add some insight.. Kyle "Blow me" | ||
| frank berry (Spencer) New Member Username: Spencer Post Number: 3 Registered: 02-2003 |
on initial start up there seems to be a lifter tap for about 3 seconds then it clears up- the knock is not loud but you can hear it-i'm wondering if it is something i should be worried about since it's been there for a year and 1/2 and 25k of use? | ||
| Kyle Van Tassel (Kyle) Moderator Username: Kyle Post Number: 42 Registered: 11-2002 |
Could very well be an issue of the term "Knock" . You might be hearing an Exhaust leak and its a knock to you. "Knock" means something different to me.. Exhaust leaks are common.. Kyle "Blow me" | ||
| frank berry (Spencer) New Member Username: Spencer Post Number: 4 Registered: 02-2003 |
well i replace the left side intake manifold do you think the right might have a crack as well? | ||
| D. Chapman (1hank1) New Member Username: 1hank1 Post Number: 5 Registered: 02-2003 |
My truck has knocked since the first off-road trail. The gasket on the drivers side cat. will not seal. I have tryed 3 gaskets and still can't get it to seal. The first time I heard it it was a little scary. Thought I had done something bad. | ||
| Tbow (Tbow) Member Username: Tbow Post Number: 43 Registered: 12-2002 |
Spencer You must have replaced the left side exhaust (not intake) manifold. If your getting the noise only on acceleration, you might have either a crack on the manifold or your gaskets are leaking. Why did you replace the manifold? Was the old one bad? Did you use a new manifold? You need to define whether it's a tapping or knocking sound. If it's tapping it could be a rocker arm going. If it's a solid knocking then it could be something totally different. | ||
| frank berry (Spencer) New Member Username: Spencer Post Number: 5 Registered: 02-2003 |
yep it was the exhaust mani not intake sorry -bought an oem one from roverconnection -new- it had a crack in it - it's hard for me to tell the diff between the tap and knock -it might be more of a tap but heavier than a lifter if that makes sense-if it's a rocker arm going out could it have been doing so for the last 25k of miles? | ||
| Geoff 93 RRC (Geoff) Member Username: Geoff Post Number: 45 Registered: 11-2002 |
I've been playing around with my engine try to find the knock under acceleration too. Engine timing and how well the exhaust is sealed at the y-pipe to manifold seems to have the most effect on changing the noise. My guess is its some kind of exhaust leak. | ||
| Tbow (Tbow) Member Username: Tbow Post Number: 44 Registered: 12-2002 |
After you replace the exhaust manifold did the noise continue, change or start. An exhaust leak can sound like a tapping or kind of a puffing sound usually heavier under acceleration. If it's a rocker / lifter it would be a constant ticking / tapping sound and should increase and decrease with the engine speed. Yes it could be steadily getting worse over time i.e. 25K miles. Lifter or rocker will will have very similar sounds. Engine knocking from low octane fuel would be a like a pinging / knocking sound heaviest during acceleration but stop when you let go of the accelerator. Hope this helps narrow it down so you can get the proper troubleshooting. | ||
| frank berry (Spencer) New Member Username: Spencer Post Number: 6 Registered: 02-2003 |
Thanks guys-- it must either be from a small exhaust leak or gas ping - |
