Author Topic: not-my-engine running smoother than my-engine (Read 3466 times)

gropar · « **on:** February 08, 2005, 07:54:29 pm »

is that clear? :roll:

I have been using my dad's old (400 000 km) 1.6td jetta and I found the engine to run MUCH smoother and MUCH quieter than my 1.9 idi.

Ok, I have almost no muffler on my 1.9. But is that enough to explain that it would never rev up as quietly and smoothly as the 1.6?

The later I will gently push up to 4000 as I would with a gasser. It also has half the highway noise level. Mine will go 'gently' up to 3000rpm : after that, it growls, ti pearces the ears, it vibrates, it seems like it's about to burst out of the hood.

I really wonder if the exhaust could do so much difference or if there is somtehing else (what?). I figure it does as far as noise is concerned. But it should not cause any more vibrations.

The beast is at the garage now. The pump at the shop for a full rebuilt, and the injectors waiting to be dismissed (should be tested tomorow -- but I have good reasons to believe they are to be changed). We'll see how it goes after that. :?

jtanguay · « **Reply #1 on:** February 10, 2005, 07:53:26 pm »

maybe check motor mounts??? mine rattles so bad... but i'm pretty sure its bad compression (and bad glow plug since it misfires at startup until a minute or two have passed and it will idle normally...)

from idle to around 3k rpm its got some good rattle to it. Highway driving is very smooth, and yes I do think muffler would have something to do with it being *loud* lol. I take it your 1.9 isnt turbo. If it was you'd gain a lot from having no muffler. One thing that it could be as well is an exhaust leak. Maybe the exhaust headers are damaged?

Dr. Diesel · « **Reply #2 on:** February 10, 2005, 07:56:38 pm »

the much larger stroke of the 1.9L might have something to do with it.
Where are you located?

QuickTD · « **Reply #3 on:** February 10, 2005, 08:31:10 pm »

I find 1.9TD's a bit "thrashier" than 1.6's and a little more reluctant to rev. Could be just the long stroke.

You might want to check the flex joint on your exhaust, they stiffen up as the bellows fill with soot. This causes the exhaust to resonate. Usually worse at ~3000rpm. Sometimes just getting under the car and wiggling it around to free it up will bring some relief. I finally cut the short flex joint out and replaced it with a much longer one, problem solved for good. A good way to diagnose this condition is to get your buddy to place his/her foot on the tailpipe while you sit inside the car and rev the engine.

gropar · « **Reply #4 on:** February 10, 2005, 10:41:22 pm »

Thank you pals!

Here is what I shall look at :

1° motor mount;
2° exhaust flex joint : wich I do not have on my 'custom' pipe :roll:
3° long stroke : can't do a thing about that, but it still explain the trashines (perfect word, Quick TD)

jtanguay : it IS a turbo engine; the lack of flex joint may cause au leak to the 'clip joint' of the down pipe, though.

Dr. Diesel : I am from Montréal, where it is cold and snowing.

Since the car is in the shop, I wil have the mounts look at. When I'll take back, I will soon have the downpipe "flexed-up".

Thanks again. I will keep you informed.