Karcher K2 Pressure Washer - pulsing problem

Turn off the garden tap and disconnect the garden hose from the machine. Then run the machine for one minute using the trigger. Detach the machine hose and run it for a few seconds further(it will run without the machine hose attached).

 

I found this thread because my same model Karcher started pulsing. I read this thread and was thinking any repair might be more than a basic pressure washer anyway - don't use it much. May as well skip it. But I found elsewhere an explanation that the nozzle on the end is the most frequent cause of pulsing and needs to be simply cleaned with a pin or paperclip. Basically a splinter or in my case a bit of moss easily jams the head and causes the pulsing as the blockage is detected. It sounds like a motor fault as the sound comes from there but 2 seconds with a paper clip and my pulsing stopped. Two hours later on a mucky job, happened again - dislodged the dirt and off again no problem. Also read the nozzle can wear out and a new lance will sort the problem. Worth trying before you skippit.

 

I see this thread is from 2017 & has been dug up.
But hope this helps other peeps.
This is what your problem is.
Replace the manifold complete.
Its the seals & the 3 bits coloured orange that fail.
I just did my one couple of weeks ago, was pulsing like mad.
1 hours job & done.

 

Having now found this thread (too late), I already replaced the control head and cleaned out the inlet filter, I can confirm that problem with my unit was also the nozzle. It made the pump pulse when in use. I’ve replaced the Nozel rather than cleaning it out and the system works fine now.

 

Trying to get to front of this thread because lot of complicated advice on here and the commonest reason for pulsing is a bit of debris stuck in the nozzle at the end. Poke it with a paperclip or similar and it'll probably be fine. Try that before chucking, disassembling, buying bits....

 

I've just repaired my Karcher washer which was pulsing in use and letting water by whether it was on or off at the switch.

In my case it was an O-ring in the trigger assembly - the small one on the cone shaped valve into the short lance section had split. I replaced them all whilst I was in there using parts from stock but no doubt you can buy a service kit.

Good as new...