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General Information => Troubleshooting => Topic started by: shaskill on December 26, 2007, 02:06:47 pm

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: shaskill on December 26, 2007, 02:06:47 pm

Bought a good looking 82 caddy with a rebuilt motor and a 5 speed from a gas engine caddy. Power seems better than my worn-out Rabbit diesel but I am getting 37 mpg while I was getting 43 mpg on the worn out Rabbit with a 4 speed. What is reasonable? I am trying to keep a light foot. I had a mechanic with experience in VW diesels check the injector timing and compression. Timing right on and great compression. Starts as soon as you turn the key! :roll:

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: jtanguay on December 26, 2007, 02:42:13 pm

i would still suspect timing, and injectors.  maybe the rebuilder just re-used the injectors without touching them? bad spray patterns can cause engine damage, and off breaking pressure can affect timing (by breaking at the wrong pressure, which in most cases increases the timing significantly due to the spring being weaker)

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: jtanguay on December 26, 2007, 03:58:03 pm

Quote from: "libbybapa"

How recent was the rebuild?

Andrew

ah true good call.  the extra mileage won't realized until well past 10'000km or even more.  (depending on how hard you 'break' it in)

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: blkboostedtruck on December 26, 2007, 05:22:56 pm

sounds like your gas tranny? thier geared lower! what tranny code you have? it's stamped on the bottom of the bell housing! post that and we can tell you more ?  or you can check your self what you have at www.scirocco.org/gears/

thanks Duane

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: shaskill on December 26, 2007, 05:40:18 pm

1. 1500 miles on a rebuild
2.will check the tranny when up on lift.
3. injectors might be OK as it starts faster than my wifes beetle TDI
4. seems to put out a lot of white smoke when climbing. At night it is impossible to stop the smoke and still keep speed up.
5. seems to blow air into coolant so am worried about the head gasket.
Thanks all!

Title: Re: Fuel Mileage Terrible on Rebuilt Caddy
Post by: jtanguay on December 26, 2007, 07:20:50 pm

Quote from: "shaskill"

5. seems to blow air into coolant so am worried about the head gasket.

open the bottle cap (when engine is cold obviously) and then put it back on.  start up the engine for about a minute and then open the cap.  if there is pressure its quite possibly the HG.

what rpm's are you running on the highway?  around 2800-3k is most efficient.  above that is fuel hungry mode.

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: Slave2School on December 26, 2007, 08:24:09 pm

Also the caddy will be less aerodynamic.

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: jtanguay on December 26, 2007, 10:32:40 pm

you guys think maybe that he might need to re-torque the head? because of the hg issues?

Title: Fuel Mileage Terrible on Rebuilt Caddy
Post by: Baselyne on December 27, 2007, 08:37:06 am

bentley states to tighten then and re-tighten then in 30 minuites or whatever.... Did you use the proper tightening sequence?