[falconpunch]

I have an 85 MK2 golf with a 1.6D with 200k miles on it (assuming original but may have a newish head) and a 82' pickup with the same engine (~82k from an 82 jetta and driven on the pickup for 80k) and same 5 speed trans. In an attempt to figure out why the pick up is so much louder in the cab than the MK2, I did a lot of MLV/CCF/foil backed vinyl deadening and replace/realigned the driver/pass/rear trans mounts. All of this made marginal improvement to in cab vibrations and loundess. Vibrations decrease when in 4th or 5th or high rpm as it does with noise, but still very loud when compared to the mk2 golf. Does anyone have an explanation for majority of this harness difference between the two?

In addition, the MK2 golf accelerates much faster throughout the range of gear/speeds. I can hit 65mph easily even just in 3rd on a flat road and have topped out at 90mph on a cold day but rollin major coal (I know bad for the engine temps but I wanted to find out). On the pickup I can hit 75 eventually but I usually top out at 70mph and its a fight even on a cold day without black smoke. Could the gearing ratios be different?

I noticed that the IP on the golf has yellow makers marks on each nut that holds it together as if one was trying to clock each nut back after opening it up. Is this a sign that it was rebuild with some upgrades? PO of the pickup (friend of a friend that I trust the word of) rebuilt the IP on it at some point but doesn't remember how long ago.

Both cars have no AC.
Thanks for any input/insights

 

[mokoosh]

As far as power, there is much that can be tweaked and tuned at the expense of making smoke.

As far as noise... well that's everything from mounting, to sound deadening, to exhaust and everything else.

 

[fastinradford]

How are you measuring speed?
When I got my caddy I was told it was slow wouldn’t go above 75,
Turns out 75 on speedo was like 85mph on gps

Mk1 speedos notoriously under report speed.

As for noise, rolling [email protected] car IS tuned.

 

[thegave]

Could just be down to body construction. I assume the Mk2 uses thicker or stronger panels, as every newer iteration seems to. Mk2 is also going to be more aerodynamic than the truck. Perhaps it is the motor/trans mount design. The Mk2 has an actual subframe to hold the engine so there are more mounting points/bushings to dampen NVH.

 

[fatmobile]

Have someone floor the peddle (ignition off) while you watch in the engine bay and see if it's hitting the max RPM stop.
Got clear fuel lines?

What kind of noise?
More clackity? Or just louder?

 

[Butcher]

No matter what, a stock 48-52HP diesel is not fast. IF you could get to 75mph, it's going to take some time and I suspect a tailwind or drafting behind another vehicle. I doubt if it's the gearing, you just need power to go faster. The amount of additional power goes up a lot as you go faster.

Rolling coal to go fast is something I would not be proud of and I'm not even an environmentalist.

 

[rabbitnothopper]

fastest ive ever gotten my 1.6D caddy is 82mph reported by TWO GPS and i was literally standing on the pedal AND going downhill for the peak of this.

a different transmission would help get it up to maybe 90mph

according to the miles and speed difference from my bone stock speedometer & odometer compared to a gps: its exactly 5% slower
the mileages were calculated over extended periods (not just a trip around the block)
and the speed difference observed on extended 12+ hour trip

furthermore, a mk2 diesel might have different specs than what the earlier solid lifter 1.6D offered


... noise? everything in a mk1 makes noise. i dont listen to the radio, i listen to the engine and noise when i drive. because im insane

 

[Butcher]

You got a radio? Heck, I don't even have a dash, carpet, headliner. Dang, living large.

 

[MattRabbit]

When I drove my Rabbit full time in college, it would cruise on the freeway at 65mph without any issue at all. 70 was sort of pushing it. I did have it up over 80 once, but again, tailwind, downhill, blah blah. These days, it'll barely do 60. I'm definitely having a power drop somewhere. That's something else to look at in the coming months.

 

[jackfolstam]

In my Mk1s, it is pretty darn loud in the driver seat. If I lean forward or move the seat all the way up to the steering wheel, it is noticeably more quiet. Also quiet in the back seat of the hatchback. So it's just by coincidence that all of the sound waves add up right where my ears are when driving.

Two of my friends went pretty serious with the sound deadening in their Caddy's, but the sound to me is the same as my car and truck.

I want to make a fully sealed skid plate and I'm thinking that will change the harmonics, hopefully for the better. I did squirt some silicone in each of the holes in the firewall where stuff passes through to try and seal the firewall. I also got some sticky back foam and am considering sealing the side and front edges of the hood to a) seal the noise in and b) get a 0.01% improvement in aero. A full car length skid plate should make a big aero difference too. Another somewhat easy thing I'm considering is lining the whole rain tray with something to help with noise, just how to do it that won't seal in moisture and promote rust..

 

[dubdaze68]

The NVH is vastly different between a Mk1 and 2, especially the pickup. Make sure that you have at least two foot by foot squares of asphaltic sound deadening on the roof panel right above the seats. That will literally make tons of difference, the factory had them there.

 

[dubdaze68]

BTW, I talk from experience. When I first bought my truck, there was only one of the pads left on the roof. First warm day we had, it started to peel off, and then I went to get in one day, and it was laying on my seat. I thought nothing of it, and started the truck to an utter cacaphony of noise, it sounded like a paint can being mixed with ball bearings in it, like it was running an open dump right behind the engine....And that was a gas engine. Two squares of Dynamat took care of it. It was amazing the difference. The truck cabs drum like nobody's business.

 

[fatmobile]

I painted my Rabbit roof with cool seal.
Before that it sounded like a tin can every time I close the door.

 

[mokoosh]

Yeah, MK2s suck, you can barely hear the turbo. 😄

By MK4 you can't even tell if the engine is running. All you can hear is the stereo. 😪

 

[Butcher]

Seriously, gas engines are getting louder and diesels quieter. They all sound about the same now. Eventually, diesels will be non existent so they will be as quiet as EV. Gas engines will soon follow.