DIS pack and leads changed no change!

[megaomega123]

Managed to change the dis pack and leads today but have no change in the symptoms.
They are: Very noisy exhaust, exhaust shaking and shuddering when pulling off. Exhaust is popping at times. Engine sounds smooth through the range. Power is down and consumption is very bad 13mpg average.
Should I now presume that it is a cat or both that need replacing?  

[JamesV6CDX]

Rob -

COMPRESSION TEST !    [smiley=evil.gif]

[JamesV6CDX]

shaking is a misfire.

I would be telling people to check valve timing in these situations, but I'm aware we did your belt quite recently  

[megaomega123]

Hi James
What will a compression test tell me? what is the probable problem and is it economical . I need reliable transport asap so need to see if it is worth repairing or just get something else.

[tunnie]

Hi James
What will a compression test tell me? what is the probable problem and is it economical . I need reliable transport asap so need to see if it is worth repairing or just get something else.

compression test will tell you wether the head gasket is ok.

any water on the oil on the dip stick?

[megaomega123]

No water/oil mix anywhere. Everything seems dandy.

[Andy B]

....

compression test will tell you wether the head gasket is ok...

Or burnt out valves  

[megaomega123]

....

compression test will tell you wether the head gasket is ok...

Or burnt out valves  

Is that economical to fix?

[ffcgary1]

 I have the same syptoms on a veccy b that i have just fitted a 3.0 into and the engine seems to run lumpy at idle and appears to have a slight miss as you blip the throttle and then runs fine at higher revs, the fuel consuption is about 12 mpg in urban traffic. the engine that was in it holed a piston and the oil that had found it's way into the  plenium and exshust means that the cat could be shagged.

[JasonH]

Any fault codes?

[Marks DTM Calib]

Did you DEFINATELY connect the plug leads on the 2-4-6 bank up correctly to the DIS pack.

[Dave-C]

Are the plugs OK?  Even if new, still could be faulty...  could the cam belt have slipped, even though it's recently been done?? :-/

[JamesV6CDX]

compression test will tell you a lot more than the condition of the HG

It will tell you if the valves are sealing ok and moving OK, and will also give you an indication if the timing has slipped (unlikely in your case)

Also, a vacc test wouldn't hurt...

[TheBoy]

Check for fault codes (and that EML is working).

As MDTM suggests, double check HT wiring for passenger bank - the DIS wiring is not as you may expect.

[Andy B]

....

compression test will tell you wether the head gasket is ok...

Or burnt out valves  

Is that economical to fix?

Depends who dos the work. My answer was a bit flippant really -   -just giving an alternative to a blown HG if you had low compression. The last valves I bought were pattern parts  for a Hyundai & were about £15 for the 2, Hyundai wanted that each.