BlurrSpeed
Member
A little background. About 3 years ago I decided to put a new (to me) engine in my 97 Passat. The Passat engines were a lot more expensive than the Jetta TDIs & from the research I did they are about the same. It seems to work OK.
The biggest issue I had was it was down on power & will go into default mode which is like it has a clogged EGR/intake or the MAF was bad. That was not the case as the intake was spotless due to a water leak in the EGR cooler. I tested the MAF &computer wires & even replaced the MAF. Not the issue. Anyway Im living with that.
On to my real issue. On the Hi-Way after about 1.5-2 hours of driving, not hard 60-65 MPH, the engine will start knocking. Scary bad. It has done this on 3 trips in several months. It is RPM variable but has nothing to do with power or throttle position. Meaning sometimes it will knock at 45 MPH & 70% throttle or may be 40% @ 65 MPH. I have not been able to vary the throttle or speed to completely eliminate it. I just have to drive until it stops or is not so bad. There is no noticeably performance loss. It also does not change with gear shift, other than the RPM difference, so I dont think its the trans
This last time after about 30 minutes of me wondering when a rod was going to come visit me I pulled over in a Rest Stop, turn it off & let it sit for ~20 minutes. That was a mistake. Before I got back on the HI-Way it was knocking even worse. This lead me to believe sitting the engine heat soaked something that worsened the issue.
Another 20-30 minutes & I pulled off the Hi-Way into a parking lot to see if I could tell what was going on. It of course does not knock at idle or usually below 30 MPH so I got nothing. This was about 5 minutes sitting at idle when I drove around the lot & things seemed OK. Out on the Hi-Way the knock is there but less.
In all cases I never have performance issues & the next day it drives just fine.
I have heard rod knock & a bad fuel pump knocking & thats what it sounds like however I have never seen either go away once they start. It does not sound like the piston slap I have listened to on YouTube & from what I have read slap happens more on cold engines.
This is my daily driver to work 1-1.5 hours in city or Hi-Way rush hour traffic & even after those 3 trips it does not drive any different than it did before. No knock in the city.
It has the stock 5 speed trans with 206K miles & the engine reportedly has about the same.
Does anyone have any idea from my description what this could be? Would a pump going out not knock all the time?
The biggest issue I had was it was down on power & will go into default mode which is like it has a clogged EGR/intake or the MAF was bad. That was not the case as the intake was spotless due to a water leak in the EGR cooler. I tested the MAF &computer wires & even replaced the MAF. Not the issue. Anyway Im living with that.
On to my real issue. On the Hi-Way after about 1.5-2 hours of driving, not hard 60-65 MPH, the engine will start knocking. Scary bad. It has done this on 3 trips in several months. It is RPM variable but has nothing to do with power or throttle position. Meaning sometimes it will knock at 45 MPH & 70% throttle or may be 40% @ 65 MPH. I have not been able to vary the throttle or speed to completely eliminate it. I just have to drive until it stops or is not so bad. There is no noticeably performance loss. It also does not change with gear shift, other than the RPM difference, so I dont think its the trans
This last time after about 30 minutes of me wondering when a rod was going to come visit me I pulled over in a Rest Stop, turn it off & let it sit for ~20 minutes. That was a mistake. Before I got back on the HI-Way it was knocking even worse. This lead me to believe sitting the engine heat soaked something that worsened the issue.
Another 20-30 minutes & I pulled off the Hi-Way into a parking lot to see if I could tell what was going on. It of course does not knock at idle or usually below 30 MPH so I got nothing. This was about 5 minutes sitting at idle when I drove around the lot & things seemed OK. Out on the Hi-Way the knock is there but less.
In all cases I never have performance issues & the next day it drives just fine.
I have heard rod knock & a bad fuel pump knocking & thats what it sounds like however I have never seen either go away once they start. It does not sound like the piston slap I have listened to on YouTube & from what I have read slap happens more on cold engines.
This is my daily driver to work 1-1.5 hours in city or Hi-Way rush hour traffic & even after those 3 trips it does not drive any different than it did before. No knock in the city.
It has the stock 5 speed trans with 206K miles & the engine reportedly has about the same.
Does anyone have any idea from my description what this could be? Would a pump going out not knock all the time?