# Another Karcher pulsing thread



## tlzeebub (Feb 13, 2008)

Quite how Karcher came first in The Gadget Shows test is beyond me, my K5.55m was pulsing when idle so ive just fitted a complete new cylinder head and its stopped pulsing when idle but now although the pressure is much improved it now pulses when active, arrrrgh anyone got any ideas please, tia Chris


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## LeadFarmer (Feb 23, 2011)

My previous Karcher sometimes did this, to some extent or other. I always wondered if it had anything to do with the water pressure from the supply tap. It sometimes felt as if there wasnt enough water being supplied?


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## tlzeebub (Feb 13, 2008)

Think I may have answered my own question, the jetwash works fine with the blaster attachment fitted but as soon as I fit the vario lance it pulses but only on a setting over half way so maybe I need to buy a new lance.


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## chrisw87 (Feb 6, 2011)

@leadfarmer, 

exactly that maybe? I've never had an issue with PW pulsing unless there was a flow issue or if it was excessively worn out (we have a 10 year old standalone commercial unit at work that has seen easily over 15 000 hours usage) still going strong but does pulsate at idle.


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## Jenko1 (Mar 23, 2011)

LeadFarmer said:


> My previous Karcher sometimes did this, to some extent or other. I always wondered if it had anything to do with the water pressure from the supply tap. It sometimes felt as if there wasnt enough water being supplied?


I use to think that about my Karcher KB9040, which I think is basically the same model as a K5.55 "barrel" type machine, that is until I upgraded to a new pressure washer with slightly higher flow rate (Karcher HD 5/11c) and that works fine. I tried a Nilfisk E130.2, which also worked fine. So I though I would measure the supply, just for fun. One bucket, tap fully open, one minute, then multiply by sixty to give l/hr. I found that the supply was almost double the flow rate of the pressure washer maximum output, so no problem there. Conclusion was that the KB9040 was trying to overachieve maximum flow-rate/pressure when new, which caused the trigger-on pulsing. Not really an issue, but nevertheless annoying during use.

BTW, the KB9040 eventually split its head after about 4 years and no longer pulses with trigger-on (it cannot achieve anywhere near it's maximum flow-rate/pressure), but now pulses with trigger-off, hence the new machine. With the new machine, I intend to always disconnect the HP and LP hoses, and then drain with a brief switch on and tip of the machine before storage. Hopefully that will clear most of the internal water and create some air voids for any ice to expand into, rather than causing possible breakages.


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## LeadFarmer (Feb 23, 2011)

tlzeebub said:


> Think I may have answered my own question, the jetwash works fine with the blaster attachment fitted but as soon as I fit the vario lance it pulses but only on a setting over half way so maybe I need to buy a new lance.


My K650M used to be the same, if I had the lance set at highest power it would sometimes pulse, had to turn it down just a tad to prevent it.



Jenko1 said:


> I use to think that about my Karcher KB9040, which I think is basically the same model as a K5.55 "barrel" type machine, that is until I upgraded to a new pressure washer with slightly higher flow rate (Karcher HD 5/11c) and that works fine.


Ive just treated myself to the HD 5/11C, only had chance to use it once, but seems a great machine.


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## indiebands (Apr 2, 2011)

LeadFarmer said:


> My previous Karcher sometimes did this, to some extent or other. I always wondered if it had anything to do with the water pressure from the supply tap. It sometimes felt as if there wasnt enough water being supplied?


I had not thought about the question of whether the water supply is adequate. Is a normal garden hose spicket enough to supply a K 5.520 with enough water? I guess I could do a flow test... Thanks.


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## Jenko1 (Mar 23, 2011)

LeadFarmer said:


> ...Ive just treated myself to the HD 5/11C, only had chance to use it once, but seems a great machine.


Totally agree - the Karcher HD 5/12c seems a good and solid piece of kit. I just need to figure out a way to easily/cheaply wind the excellent HP hose.

I had the Nilfisk E130.2 for a week before taking it back. Although it's a nice machine, I just didn't like the plastic HP hose or click and clean nozzle system, and the fan pattern of the supplied nozzle was a bit undefined for me.

Apologies to O/P for going a bit off the original topic - cheers


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## LeadFarmer (Feb 23, 2011)

Jenko1 said:


> Totally agree - the Karcher HD 5/12c seems a good and solid piece of kit. I just need to figure out a way to easily/cheaply wind the excellent HP hose.


Yeh, thats the only annoying thing ive found with the machine, nowhere to store the hose! Wouldnt have hurt them to have put a couple of hooks on it:wall:


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