Author Topic: Vibrations... and not the good beach boys kind (Read 7132 times)

Deutschbag · « **on:** June 03, 2008, 09:57:26 pm »

Hope I'm posting this in the right section. I've got a n/a 1.6 IDI in my 81 vw caddy and it vibrates. A lot. The entire dash seems like it's gonna fall off. It's only really bad at idle though, and this is hot or cold. I've been reading up and realize it could be a number of things: timing, compression, bad injector, motor mounts, etc. If my car seems to be running fine and pulls hard, what should be my first course of action? The motor mounts "look" okay, thought I can't really see in there all that well. The injection pump and the entire cylinder head are both recently rebuilt by a reputable shop, so the compression and injection "should" be good. The guy said he had the timing advanced a bit for easier startups, not sure by how much. If you guys could let me know what I should look at first, I'd very much appreciate it. Thanks in advance!

Here's a picture of the caddy if you're bored:

Vanagoner · « **Reply #1 on:** June 04, 2008, 05:14:57 am »

nice caddy- I especially like those wheels on it.
I'd say increase your idle speed until it is better.
your location?

subsonic · « **Reply #2 on:** June 04, 2008, 05:19:17 am »

How old are the motor mounts?

shegel · « **Reply #3 on:** June 04, 2008, 08:20:40 am »

my golf would be fine at idle and shake horribly when driving...(sound familiar) it was the front mount.

rabbitman · « **Reply #4 on:** June 04, 2008, 10:46:09 am »

The passenger side motor mount is usually the culprit.

jtanguay · « **Reply #5 on:** June 04, 2008, 12:40:29 pm »

Quote from: "shegel"

my golf would be fine at idle and shake horribly when driving...(sound familiar) it was the front mount.

sometimes that can be struts though too... but will be more noticeable at high speeds

Deutschbag · « **Reply #6 on:** June 04, 2008, 01:43:39 pm »

Well the car seems to be idling kinda high already, so I don't think it's necessarily the idle speed itself that's causing the problem, but I'll play with it later. I'm in the middle of a vacuum pump rebuild and I broke the hose on the positive pressure side of the pump so I gotta wait for a buddy to take me to the parts store, don't wanna spew oil all over my squeaky clean engine bay.

Upon closer inspection of the mounts, they do look cracked. The only one I can really see is the tranny side mount, there are definitely cracks. I guess I'll start with the mounts and move on to more in-depth things from there.

FYI, the car is only vibrating hard at idle, it runs amazingly well at speed, albeit a bit noisy from an exhaust leak.

Deutschbag · « **Reply #7 on:** June 22, 2008, 01:37:39 pm »

So anyone got any more thoughts on this? Reminder, it only vibrates like crazy at low RPMs (idle and just off idle), while running on the freeway and such it's just loud because of an exhaust leak.

Dakotakid · « **Reply #8 on:** June 22, 2008, 05:05:48 pm »

No, just the thought from above...the front mount rubber is split and it is now a matter of metal on metal inside the mount. The others are probably fatigued as well. Straight forward advice here. Been there....done it....stuff.

Deutschbag · « **Reply #9 on:** June 22, 2008, 09:42:12 pm »

Ok, I'll tackle the motor mounts first. What's the general consensus on motor mounts, HD style from Black Forest Industries (not poly, just HD), or stock?

FWD.MOTION · « **Reply #10 on:** June 26, 2008, 08:14:52 am »

hummm good to know...does poly and HD really make a huge differance?

which one would be the best one to get if I was to buy them one at a time?

jtanguay · « **Reply #11 on:** June 26, 2008, 04:13:46 pm »

go with a passat front mount if you want longevity... they'll last forever... but be warned they will vibrate a bit more.

FWD.MOTION · « **Reply #12 on:** June 28, 2008, 07:38:52 am »

Thanks Jay, Hey Deutschbag your trucks amazing, Im dieing to find one here canadian side!

I got the front mount and Installed it today. Took it for a drive before tearing my IP apart to get the seals re-sealed up! On the viberations note, I defonetley think the poly front mount will rattle your starter bolts right outa the bellhousing!

but apon a dumping the clutch in any gear the torque transfer feels like it goes stright to the stearing wheel....solid solid upgrade

which mount is most important after doing the front one as alittle more money came in my mailbox but im still too poor to buy more than one at a time....

which will I notice most out of the passinger side mount, or top driverside mount, or lower trans mount?

burn_your_money · « **Reply #13 on:** June 28, 2008, 08:04:23 am »

bad injectors usually really show themselves at idle. I'd have them tested

DonGTI · « **Reply #14 on:** June 29, 2008, 02:37:31 am »

motor mount test routine...

Think it through and don't fully release clutch!!!

Put car in 1st gear and have someopne look at the motor with hood open
Pull parking brake/handbrake
foot on brake pedal
Slowly release clutch

IF the engine starts lifting up from the front, te its propbably front mount... looking at it closer you should see it being pulled up

if the engine sinks at the firewall/bulkhead thing then one of the 2 rear mounts is the one gone

in this case put car in reverse and re-do the brakes

try again and if the engine lifts from the back then one of the rear mounts is wrong... differenciate between which one by looking at which side rises most i.e. engine side or transmission side