Hi Folks.

I put an S4 short block in a S5 car. The engine finally runs - more or less smooth.
But heres the problem:
If I rev the engine I can hear some metallic noise at high revs (about +5k). If I drive the engine the noise seems to appear already at lower revs (+3k) and the engine lacks power.
First I thought it could be the alternater but it isnt. How does it sound if the engine knocks? Because the car sat for 4 years - so the fuel is old (I will put new one in tomorrow). What else could it be? Im not shure if I put the fuel sockets (the plastic ones below the fuel injectors) in the opposite direction -> anyone experience on this?
Also the engine seems to produce a lot of heat -> the pre-catalytic converter starts to glow a little bit already without even driving the car! Is that normal?

Harry

 

Metallic rattling sound = detonation.

Start by checking if the leading/trailing plug wires are swapped.

(Yes, it happened to me once.)

 

I agree, make sure your plugs are all the way in and tight as well. its happened to me on more than one occasion.

 

i am guessing it has somethin to do with 4 year old fuel. the lack of octane maybe causing the detonation.

 

gas that is older than 6 months is garbage, get freash clean gas with a new fuel filter first, that way you can rule out fuel problems.

 

Hi.

Thanks for your replies. The ignition system was the first thing I checked - spark on all plugs and everything sits tight - although its strange if I unplug the Trailing Coils that seems to have no effect on the engine at all... Will change the fuel today - maybe its really detonation. Its a high pitch metallic ratteling - like something is scratching anywhere. Will update you this night.

Harry

PS: What about the glowing pre-converter?

 

clogged cats can kill ur performance..

run open exhaust and see what happens..

but first drain ur gas, put some fresh stuff in, change the fuel filter (or run it direc temporarily for the test)

check again, and see what happens...


the car will run without Trailing plugs.. that's normal... don't worry about it...

 

Duh, you're running on varnish by now...

Please use a little common sense.


-Ted

 

10 years ago you could store gas for a year.

Todays formulations start to seperate after 2 months.

My 64 Midget project had gas in the tank from 1967.
It was still good enough for the lawn mower.
No way today's fuels would do that.

 

Ok. Put new fuel into the tank - didnt change a thing... This weekend I will take of the UIM to see if I put the plastic fuel diffusers of the primary injectors in the wrong direction. Also I will take off the drive belts for the air pump/alternator to see if one of those causes the metallic noise.

Harry

 

Ok. Weekend is over - problems arent.

I pulled the UIM and surprise, surprise - I really put the fuel diffusers 180 degrees in the wrong direction. I also took a look at the main converter -> about 1/4 was clogged with some hard stuff -> put a "new" old converter in. Result -> the engine turns smoother till redline (while the car stands still!) But same problems while driving. Still missing power and under heavy load the metallic noise still appears. I unhooked the PS and air pump - so I guess its the water pump, because if it would be the alternator I think I could locate it more precise... So, lets wait for the pump - will take at least 2 weeks :-(

Harry

 

This is almost impossible.
The "diffusers" are either damaged, or your engine is pretty screwed.
The "air bleed valves" are keyed and are supposed to be able to be inserted one way.
If they are not pushed all the way down, the fuel injectors are sitting too high and will not seal well causing a huge intake leak.


-Ted

 

yep, I noticed later, that they are keyed. But the 2mm dont seam to make such a difference and you can put them in the wrong direction! Nevertheless its a PITA to push them down anyway.

Harry

 

Hi.

Yesterday I took the car for a longer test drive to see what it does - so I finally can say it has no power at all. Wont rev above 5.5k from 2nd gear on, although I can make 80mph if I am patient...
I have the following suggestions:
some vac lines connected wrong, ignition heavily misaligned, UIM gasket leaky?
I also noticed that the fuel pump already runs if I put the key in ON position without starting the engine. So can it be that the pump gets constant voltage even under heavy load and doesnt supply enough fuel?

greetings,

Harry