Clyclic revs on acceleration

SimphiweB
Vehicle: Pajero 3.2 DID,GLS, 2007,LWB
Country: RSA
Posts: 10
Joined: Tue Dec 12, 2017 9:28 am

Clyclic revs on acceleration

Fri Mar 23, 2018 10:39 am

Hi

My car has intermittent cyclic revs on acceleration especially in the mornings . There is no loss of power , no dash warning light and it idles perfectly. This cyclic rev can disappear for many months and come back. I cleaned the SCV before and it went away but im not sure if it was just a coincidence. I took it for a service yesterday and it got scanned for faults but nothing was found to be wrong, but this morning the cyclic revs came back. It does this in the morning particular when i warmed up the engine before driving off . It also happens without fail a day after an oil change or service, strange enough. The revs last for less than a minute but are very noticeable. Could this be a sign that my Suction Control Valve needs to be replaced or its the Oil Pressure Sensor? Dirty fuel perhaps since i filled up after the service? I was hoping that it could be picked up by the scanner during the service but it never did.

Please advise.

Pajero DID 3.2, 2007 GLS
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4ePikanini
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Vehicle: 2001 Pajero LWB 3.2 Di-D GLS
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Re: Clyclic revs on acceleration

Thu Mar 29, 2018 9:35 am

definitely SCV

Just replace it and call it a day.

PS : I assume you have already replaced the fuel filter as a precautionary?
Marius Fourie
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2005 Touareg R5 Air & Bi-Xenon
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SimphiweB
Vehicle: Pajero 3.2 DID,GLS, 2007,LWB
Country: RSA
Posts: 10
Joined: Tue Dec 12, 2017 9:28 am

Re: Clyclic revs on acceleration

Tue May 15, 2018 1:24 pm

Hi Marius, you were right, I replaced the SCV and the car came back to life.

I have a small oil leak under the turbo. Its very small, just a sweat of oil around one of those metal downpipes. Is it something to worry about? it comes and goes but I've not been able to link the pattern to anything. I will appreciate advise from members.

I will have a timing chain replaced in the next few days, the mechanic noted so metal rattle and we have worked on most of the possible causes except for the timing chain. This rattle can be heard clearly when the engine is under load at highway speed. I will also have the valve clearances looked at since they have never been done, the car stands at 253000km.
Tony M
Vehicle: 2008 Pajero GLS LWB
Country: South Africa
Location: Cape Town
Posts: 21
Joined: Sat Oct 29, 2016 3:06 pm

Re: Clyclic revs on acceleration

Sun Jun 03, 2018 10:13 am

Hi SimphiweB,
I have a problem where my 2nd hand 2008 Gen 4 Pajero (235K KMs) exhibits a gentle 'Rhmmm, Rhmmm, Rhmmm' noise under acceleration.
It's not a loud noise and I can't see any change in the rev counter, but, unlike your problem, it's always there.
It's fairly easily heard at around 110 KM/Hr but might come in at around 80 KM/Hr or so or even lower speed.
Not heard under heavy acceleration (probably due to engine noise) but on a flat road with just enough pressure on the accelerator to keep the car at 110 Km/hr it's constant with about two to three 'Rhmmms' per second increasing in rate the faster one drives.
Complained to the dealers multiple times but they can't figure it out - or just ignoring the problem. :(
Have spent Rand thousands thus far, over the 18 months I've had the vehicle, taking the car to various places and having 'evaluations' done so now I'm looking to identify myself.

Just wondering if your symptoms were the same and it might be the SCV that needs replacing?
BTW, how much did they charge you for your SCV replacement, if you don't mind me asking?

Thanks!
Tony
SimphiweB
Vehicle: Pajero 3.2 DID,GLS, 2007,LWB
Country: RSA
Posts: 10
Joined: Tue Dec 12, 2017 9:28 am

Re: Clyclic revs on acceleration

Mon Jun 04, 2018 8:58 am

Hi Tony

Yes my problem was sorted out by replacing the SCV. It cost me just over R4500 from the dealers. Its a DIY job, it took me 20min to replace it because I had been accustomed to cleaning the old one so I knew exactly what it took to replace it.

The old one had some scouring on its small shaft which could be the reason why it was not pulsating well.

Also check if your EGR is clean and confirm if your butterfly valve in the throttle body works like its supposed to. I initially thought the throttle body was not functioning until I learner that it starts kicking in when the car engine is at operating temperature.

Thanks,

Simphiwe
SimphiweB
Vehicle: Pajero 3.2 DID,GLS, 2007,LWB
Country: RSA
Posts: 10
Joined: Tue Dec 12, 2017 9:28 am

Re: Clyclic revs on acceleration

Mon Jun 04, 2018 9:11 am

Hi Tony

Just to add; I also sent my car for scans, including at the dealer, and they didn't pick up any code. Fortunately , Marius, one of the members on this forum, pointed at the SCV as the possible culprit. This forum has been a valuable source of information for me, I was on the verge of getting rid of my car because of silly technical problems. I have learned to anticipate problems and do preventative maintenance. Mine stands at 254km now, hoping to get to 350km. I should have injectors checked soon and also get ready to get a new water pump.
Tony M
Vehicle: 2008 Pajero GLS LWB
Country: South Africa
Location: Cape Town
Posts: 21
Joined: Sat Oct 29, 2016 3:06 pm

Re: Clyclic revs on acceleration

Mon Jun 04, 2018 10:47 am

Thanks SimphiweB

I've replaced the air flow sensor, engine mounts, gearbox bushes, front upper ball joints and recently the rear right wheel bearing plus had a number of dealer services (no fault codes) - and of course visits to 3 wheel balancing outlets.
On the rear wheel bearing, the dealers didn't pick it up as a problem although personally jacking the car up I found it was not just bad but rattling. Dealer said they had checked the wheel bearings - but with the handbrake on :shock: - they've now 'amended their procedure'.
Also found the turbocharger pipe at the entrance to the throttle on the inlet manifold was loose and had been spraying gunk onto the inlet manifold - certainly wouldn't help the engine efficiency ;)
ECR seems to be working OK (no black smoke etc) although one day I'll strip the inlet manifold and clean anyway.
So I'll try the SCV valve next but I was lead to believe that the engine ECU has to be 'reset' or otherwise 'updated' when a new one is fitted - which only the dealer can do?
Have previously spoken to the spares dept and they tell me they do sell lots of SVC's and they keep stock in CT.

Thanks for your help!
SimphiweB
Vehicle: Pajero 3.2 DID,GLS, 2007,LWB
Country: RSA
Posts: 10
Joined: Tue Dec 12, 2017 9:28 am

Re: Clyclic revs on acceleration

Mon Jun 04, 2018 11:15 pm

Hi Tony

I did not have to go to the dealer for ECU reset after installing my SCV. I reset mine, google how to reset a pajero ECU you will get tips. Its not complicated, just a few steps that involve battery disconnection and idle. I was told by the dealer that I don't need to come to them for a reset when I bought the SCV. My car was fine unless its still going to give me trouble, more than 1000km since I changed it.
Make sure that you replace your short/long SCV with the same length SCV, otherwise it may give you problems if you use a different one from the original. Better look for a Denso SCV which will go with your Denso pump.
SimphiweB
Vehicle: Pajero 3.2 DID,GLS, 2007,LWB
Country: RSA
Posts: 10
Joined: Tue Dec 12, 2017 9:28 am

Re: Clyclic revs on acceleration

Mon Jun 04, 2018 11:23 pm

Hi Tony

Perhaps while you are at the dealer, consider getting an oil pressure sensor, its cheap around R200, Its right next to the SCV on your car model, I think. It needs a 24 deep socket, 5min job. Its a maintenance item because if it goes you will be trouble.
Tony M
Vehicle: 2008 Pajero GLS LWB
Country: South Africa
Location: Cape Town
Posts: 21
Joined: Sat Oct 29, 2016 3:06 pm

Re: Clyclic revs on acceleration

Tue Jun 05, 2018 8:25 am

Thanks once again SimphiweB!

I'll give it a shot at some time and see what happens.
I'm tackling 'one task at a time' to eliminate variables.

Right now I'm waiting for some rubber door 'stoppers' from Japan.
No idea how they came to be missing from the rear passenger door and the back door.
Such is what one gets when one buys second hand.

Kind regards,
Tony

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