gday
i think my '87' 740 turbo might have a problem when under pressure. first of all there is a hole in the hose coming from the turbo going into the intercooler about the size of a fingernail, this cant be the problem (i dont think). im going to replace them this weekend. my problem is when i take of and the turbo needle goes to about 12 o'clock (just when the yellow bit starts)it takes of really well, and u can feel the turbo kick in, but when u are going at about 40km/h and flattern it the needle goes as far as it goes but nothing happens, even when u built the boost up and than under full throttle the same thing happens, the needle goes up but nothing happens then when u back off and keep the turbo in the yellow then it gets a kick and goes but if u plant it again the same thing happens. i dont know if this is just really bad turbo lag or what, but im pretty sure its not ment to happen. the old motor which was in the car didnt do this and since ive had it replaced ive noticed this. the motor starts fine although coming home from school this afternoon i was at a round about and i went to go after stopping and it started to miss and stared 'coughing' another thing is that the engine bay has a strong smell which is noticeable from the drivers seat, could this be a leak in the exhaust system?
thanks in advance brownie

I recently had a fingernail size hole in the hose leading from MAF to turbo cause 1) loss of boost and power over 4500RPM and 2) a no-start in the morning.

Jack

As Edmund said, any hole in a turbo hose (no matter how small) can cause your car to do crazy things. The vacuum and turbo pressure in those hoses control your car's ignition and fuel systems. Without these two systems working properly, anything's possible.
First of all, fix the hose. Either patch it with duct tape for now, or if you have the new hose already, then put it on the car. That may fix all your problems. But even if it doesn't, you must have an air-tight system in order to diagnose anything.

Keep us posted on the progress.

Jeff Pierce
--
'92 Mercedes 190E (my daily driver), '93 945 Turbo (a kickass family car), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)

ANY holes, even pinholes in turbo hoses can affect performance. Holes the size of fingernails can make the car unroadworthy. Your case sounds pretty extreme, and although its hard to tell from your description, youre probably damaging the turbo. In fact, it sounds like your engine has some pretty serious problems-any smells are definately bad news. If someone replaced your engine recently, take it to them and demand that they fix things. If you replaced it yourself, check over your work thoroughly, its easy to miss things like zip-tie-ing wires for various engine sensors away from the engine so that the insulation doesnt get melted. Engine smells can be anything, but make sure all the gaskets on a recently rebuilt engine are properly installed and not leaking.