[SiNNeD]

I have a quick question for all you engine pro's out there and the diagnostic procedures. When a person (me) takes a car in to get say an engine knocking noise looked at and they run the "diagnostics" on the engine does the diagnostics tell all about whats going on with and inside of the engine. I mean say I have an engine knock a very faint one and it can only be heard at certain times, will the computer that the hook it up too (diagnostics) be able to tell if there is a discrepancy withing the motor? Does it tell if there is something night firing right or that there may be a rod thrown or something wrong with one of the pistons. The reason I ask this is cuz I have taken older cars that I have owned in for engine noise and they said that they could not duplicate the problem most times. But when I take my MCS in this monday and say they dont hear the noise will the diagnostics pick up on this? Any help on this matter will ease my mind. Thanx ahead of time!!

[obehave]

Quote: Originally Posted by SiNNeD

I have a quick question for all you engine pro's out there and the diagnostic procedures. When a person (me) takes a car in to get say an engine knocking noise looked at and they run the "diagnostics" on the engine does the diagnostics tell all about whats going on with and inside of the engine. I mean say I have an engine knock a very faint one and it can only be heard at certain times, will the computer that the hook it up too (diagnostics) be able to tell if there is a discrepancy withing the motor? Does it tell if there is something night firing right or that there may be a rod thrown or something wrong with one of the pistons. The reason I ask this is cuz I have taken older cars that I have owned in for engine noise and they said that they could not duplicate the problem most times. But when I take my MCS in this monday and say they dont hear the noise will the diagnostics pick up on this? Any help on this matter will ease my mind. Thanx ahead of time!!

A rod knock for example will not show directly in diagnostics. What it may do it trigger the ping sensor and retard the timing will will show as out of parameter for example.
The OBDII stuff is pretty thorough.
As always, much depends on the mechanic.

There's a couple guys here that know it inside out. Maybe this'll bump your question up and they'll catch it.

[pocketrocketowner]

The OBDII systems are the bees knees. They will pick up anything that is going or has gone wrong with all of the operating parameters of the engine, including oil pressure, oil temperature (which would be the reasons for you to have a rod knocking), and pretty much anything that your engine can transmit electronically to the system. The other side of the coin, is they can also tell if you've abused it (repeated overevving or hitting the rev limitier as an example).

[SiNNeD]

Quote: Originally Posted by pocketrocketowner

The OBDII systems are the bees knees. They will pick up anything that is going or has gone wrong with all of the operating parameters of the engine, including oil pressure, oil temperature (which would be the reasons for you to have a rod knocking), and pretty much anything that your engine can transmit electronically to the system. The other side of the coin, is they can also tell if you've abused it (repeated overevving or hitting the rev limitier as an example).

Well that would lead me to another concern then haha. The repeated revs and or the rev limiter. I dont think since I have owned the MCS that I have gone over 5000 RPM's MAYBE once but no more than that. Thats the thing is that I have a buddy that really gets on his Brit Spec MCS and he has not a ping or a knock but I baby mine with the occassional BURST of joy down a straight away and I get the KNOCK faint but still a knock that has me concerned. But thank you both, Obehave and PocketRocketOwner for your replies I really do appreciate em....

I was gonna ask the question just for GEE WHIZ purposes where people wait on the RPM's before they shift. I only ever go to about 4500 RPM's before I shift. Should I be going more or less?

[obehave]

Quote: Originally Posted by SiNNeD

Well that would lead me to another concern then haha. The repeated revs and or the rev limiter. I dont think since I have owned the MCS that I have gone over 5000 RPM's MAYBE once but no more than that. Thats the thing is that I have a buddy that really gets on his Brit Spec MCS and he has not a ping or a knock but I baby mine with the occassional BURST of joy down a straight away and I get the KNOCK faint but still a knock that has me concerned. But thank you both, Obehave and PocketRocketOwner for your replies I really do appreciate em....

I was gonna ask the question just for GEE WHIZ purposes where people wait on the RPM's before they shift. I only ever go to about 4500 RPM's before I shift. Should I be going more or less?

I live in a pretty urban area. High revs are pretty rare. I don't get any pinging. Usually shift 4Kish

[pocketrocketowner]

Knock is just no fecking good at ANY time or in ANY quantity. I am guessing if you are really hearing knocking or pinging, you need to use more premium fuel and give the engine some welly more often as well.
Two things cause pinging or knocking, (all other things being left dead stock). One is bad fuel (low octane or contaminated with say water or oil or diesel) and the other is a slow accumulation of deposits on top of your pistons (mainly) and in your combustion chamber (less so). The accumulation of these deposits will in effect increase your compression ratio, making your car need higher octane gas.
In short, more octane, more welly.....engines that get babied usually last less (though a whole lot more than those that get abused)