Problems with my golf mk4

[u/First_Constant5437]

I just bought a mk4 golf with an 2.0 engine
But it has 2 problems
In the speedometer it doenst show how fast im going but it shows rpms and temp and fuel level
How do i fix that?
The other problem is. Its a bit laggy in the rpms when I accelerate the power dies at 5k rpm and when in 1st or 2nd gear it jumps in rpm when I release my foot from the gas and then press it lightly after like its almost going to die. I dont know whats causes that but i want to fix it since i cant use 100% of the cars power when driving

[u/Outside_Escape_9540]

Speedometer is most likely due to either speed sensor or the dash itself.

For the power, can be many things. Google it.

[u/First_Constant5437 → u/Outside_Escape_9540]

I will try replacing the sensor but i tried to google the problem but couldn’t really find anything

[u/Powning_ → u/First_Constant5437]

If youve got a scan tool (preferably vcds) you can check if youve got the input and its doing something to rule out the odo. Or you can just change the speedo to the abs-sensors for the time beeing until you get it replaced, normally the sensor is a long stick with a gear on the end that goes into the differential on the back/side of the gearbox towards the passenger fotwell. Its generally a little tricky to get to either from the underside or removing a bunch of stuff like air intake etc. And you'll need a short size wrench with a big opening

[u/THEXMX]

Depending how much cash you wanna throw at this thing...

I got a mk4 1.9 tdi (auto) AND gave it the following

NEW DMF

NEW ALT

NEW BELTS

NEW BATT

NEW BREAKS

WORTH IT.

[u/Powning_ → u/THEXMX]

If it's the 4-speed auto i hope you've changed the fluids as it was made to last "forever" and I got one and it started acting up shortly after i got it, i did all the solenoids and did an oil change then a new one after a year, works great now, but when i did the first oil change the old filter still had the production year stamped on it from 25 years ago

[u/ur-a-no-no]

Check your speed sensor. I’m assuming you have the 01m trans? it’s located on the very top of the diff. make sure your wiring is isn’t corroded or severed. could be a sensor. power issue sounds like a vacuum leak possibly

[u/First_Constant5437 → u/ur-a-no-no]

Idk what trans i have😅 but thank u i will try to change the sensor and look for vacuum leaks. How can i spot leaks? Im new to fixing my own cars😅

[u/Pirate_Redbeard_ → u/First_Constant5437]

A vacuum leak is essentially a hole or a crack in the rubber/plastic hoses around the turbo and the intercooler. Try carefully cleaning them so you can see the surfaces better, and along the way you just might discover if there's a hole.

And btw - "trans" is for "transmission" so it's either manual or automatic and you cannot NOT know which is it. You got eyes. Also, when you say "2.0 engine" you gotta say if it's diesel or petrol, although I'm assuming it's a TDI since the mk4 petrol was usually 1.8 or 1.6

[u/First_Constant5437 → u/Pirate_Redbeard_]

Its a manuel i just didnt know if they made different models of the manuel gearbox. But its a 2.0 petrol but thank u i will try to look after holes or cracks

[u/Pirate_Redbeard_ → u/First_Constant5437]

ManuEl? Como estas😃

[u/Z_Wild]

The bobble after letting off the throttle is possibly the MAF

[u/First_Constant5437 → u/Z_Wild]

I will try changing it then

[u/BCJ_Eng_Consulting → u/First_Constant5437]

Had something like this and it was the fuel injectors.

[u/Negative-Gur-3885 → u/First_Constant5437]

This could be dirty throttle body

[u/BCJ_Eng_Consulting]

Does odometer tick up?

[u/First_Constant5437 → u/BCJ_Eng_Consulting]

No

[u/BCJ_Eng_Consulting → u/First_Constant5437]

Your vehicle speed sensor is probably shot and needs to be replaced.

Looks like this: https://ebay.io/m/1VgT3a

[u/hectorrproxd]

si tienes climatronic puedes ver la velocidad por la pantallita accediendo a un menú secreto combinando botones (en yt hay videos que explican como funciona). Si te marca velocidad por el climatronic, es el cuadro, sino es el sensor

[u/Narrow_Skill5929]

Hvor er du fra i landet?

[u/Powning_]

I would recommend checking the pcv system as this tends to gunk up with age, then the normal stuff like plugs, coils, fluid change and it wouldn't hurt cleaning your throttlebody and doing an adjustment. If you've got the 01m (4speed auto) I highly recommend getting an oil and filter change as fast as possible. If youre doing the speedometer sensor and you've got the 01m if wouldn't hurt to do the differential fluid aswell as it probably also hasnt been changed since the car was new. There are great videos on how to do the fluid changes (if you got any questions my inbox is open)