# Problem With A Karcher 7.85



## Mark B (May 6, 2007)

Hi guys,i have a karcher 7.85(only had it about 4 months) and have a slight problem. What happens is that when it is switched on but not being used for a moment the motor decides to start up for about 10 seconds then switches off and this tends to continue to happen!! Anybody got any ideas on how this can be rectified atall.Thanks


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## Avanti (Jan 17, 2006)

Mark B said:


> Hi guys,i have a karcher 7.85(only had it about 4 months) and have a slight problem. What happens is that when it is switched on but not being used for a moment the motor decides to start up for about 10 seconds then switches off and this tends to continue to happen!! Anybody got any ideas on how this can be rectified atall.Thanks


If you had it from new, then it will still be under warranty. :thumb:


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## timprice (Aug 24, 2007)

the same thing happens to my KB4040, but not for 10 seconds. the motor gives a pulse as if to say "you've forgotten me!", which i find quite amusing. i assume it's just the pressure being released in the hose, but not sure.

this issue happens after approx how long at idle? 1 min, 5 secs, 1 hr?

would an acceptable solution be to turn the washer off when you're not using it?


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## Mark B (May 6, 2007)

yeh i thought that but i got it off e-bay and cant remember off who


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## Mark B (May 6, 2007)

timprice said:


> the same thing happens to my KB4040, but not for 10 seconds. the motor gives a pulse as if to say "you've forgotten me!", which i find quite amusing. i assume it's just the pressure being released in the hose, but not sure.
> 
> this issue happens after approx how long at idle? 1 min, 5 secs, 1 hr?
> 
> would an acceptable solution be to turn the washer off when you're not using it?


after its switched on could be anything from 5 mins to 30 mins depends how it feels.. and yes i do turn off now when not using as its started to pee me off.


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## timprice (Aug 24, 2007)

ah yes but it will be repaired by karcher themselves under their warranty terms i believe. as long as you have the contact number for karcher's warranty dept, you should be ok.


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## Rundie (Oct 2, 2007)

Pulsing motor was a sign that part of the the plastic pump had a crack in it on my old 4.99. You'll also notice a drop in pressure, not good and the reason I went off domestic Karchers, mine was only a year old and not used loads.


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## timprice (Aug 24, 2007)

Mark B said:


> after its switched on could be anything from 5 mins to 30 mins depends how it feels.. and yes i do turn off now when not using as its started to pee me off.


ok fair enough. i would say write an e-mail to karcher support and ask the question. you might find it's by design for that model to relieve pressure or some other technical explanation.


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## Grizzle (Jul 12, 2006)

if it pulses theres a loss of pressure somewere be it the pump or fittings if its only a year old send it back asap.


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## Mark B (May 6, 2007)

Thanks for that guys, i think i'll give karcher a ring and see what they say.


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## KnightUnit (Dec 31, 2007)

Was it left out in the frost by any chance?


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## mercboy (Jan 31, 2008)

karchers dont like not being used the seals perish


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## Mugwump (Feb 17, 2008)

Mark B said:


> Hi guys,i have a karcher 7.85(only had it about 4 months) and have a slight problem. What happens is that when it is switched on but not being used for a moment the motor decides to start up for about 10 seconds then switches off and this tends to continue to happen!! Anybody got any ideas on how this can be rectified atall.Thanks


This simply down to pressure being lost (probably through a worn or perished seal). It is common on washers with auto shut off. Shouldn't be difficult to fix if that's all it is.


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## 309Goodwood (Oct 23, 2006)

I am getting the same problrm with my Karcher (k3.91) and wondered if your problem was ever resolved or if anybody has any ideas on how to repair ? My machine is about 14months old but not over used really, poss once a week for about half an hour ??

Cheers

shane


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## glyn waxmaster (Dec 20, 2006)

Dont hold your breath for decent service from Karcher

http://www.detailingworld.co.uk/forum/showthread.php?p=734845#post734845


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## Fourbears (Sep 2, 2007)

Sounds like an airlock. Do you run water through after connecting the hose and before turning the switch on? If not try it, it might work as I always have air in mine whenever I connect it.


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## Gunn79 (Sep 9, 2007)

Mine has just started doing this for the second time. First time I had to pay to get it repaired out of warranty, and now its happened again!


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## efunc (May 22, 2007)

How much did the repair cost? My one's just died.


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## PootleFlump (Jan 1, 2006)

My Karcher does this, haven't had a chance to take it apart yet, lost some pressure and pulses, I was told it's probably a crack in the plastic cylinder head costs about £20 to fix.


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