Whining noise in engine on low revs. PCV?

LT South Africa · Jul 17th, 2016, 13:38

Hi all. I have been struggling with the whining noise in the engine for some time.

Posts here indicate it's the PCV.

In summary. The engine has a terribly annoying noise at low revs. This is only when the vehicle reaches normal operating temperature.

With the engine idling there is so much force on the oil cap that it cannot just be loosened and removed without a great deal of effort.

When I extract the dip stick there is a distinct Pop as the pressure is released. And it pops back in against with ease as the pressure pulls it in.

However, with either the oil cap off or the dip stick removed the noise is gone.

I removed he PCV and found it was quite clean. But rinsed everything out including all the pipes.

Whilst disassembled I cleaned the throttle control body as well.

After reassembling I noted a huge amount of extra power. And the engine idles much smoother.

However, the noise is still there.

What do I stand to do next.

skyship007 · Jul 17th, 2016, 18:20

Try changing the oil and oil filter. Make sure it's a major brand Xw40 (Acea A3/B4) AND use a real oil filter from a Volvo dealer (Or good Internet firm like Skandix), or one of the German TUV certified companies like Bosch or Mann.

Check the fill level with the dipstick screwed in and avoid overfilling by using the correct amount of oil less a bit for the block.

If that does not sort it, then check the valve covers are not loose etc. It might also be that the dipstick or filler cap oil seal are split.

canis · Jul 17th, 2016, 23:38

You said "whining noise" - could it be that with that much suction going on, it's pulling the hose between the bottle and the manifold almost flat, causing it to rasp like a reed instrument?

I'm sure it's not supposed to suck that much though.

LT South Africa · Jul 18th, 2016, 06:28

There is no harm in doing a filter and a oil change. I will give it a try.

Trying to ascertain if hoses are collapsing will be difficult. But I will try.

Seeing as the pressure is sucking and not pushing. I am seriously considering doing a little modification and installing a "T" connector on the top hose which runs past the oil cap and into the head with a inline filter just to keep just out of the system. Which should stop the noise. Will this work?

LT South Africa · Jul 19th, 2016, 09:57

So I changed the oil filter and replaced the oil with a grade 40 synthetic. Excitedly I turned the motor and waited in anticipation for the engine to warm up. Not even 5 minutes and the noise is back at low revs.

I run a driving school with this car and the noise is attracting a lot of attention from the examiner.

I am in a rural town and about 200miles away from the nearest Volvo mechanic.

As a temporary fix to the noise. Would it be okay f I loosen the pipe from the pcv which runs into the head under the plastic cover?

Would this cause any engine damage?

Alex121 · Jul 19th, 2016, 11:34

If your PCV is blocked then it can push oil past the piston rings/valve stem seals (or turbo seals if you have one).

Classic test to check it is to get into second or third gear when driving, accelerate up to 5,000 revs then let then engine brake to around 1000 revs, staying off the brakes, then go WOT throttle - Do you get any blue smoke out the pipes....If so, it's blocked!

LT South Africa · Jul 19th, 2016, 11:48

Alex121

I had the pcv and all the pipes off on the weekend. The pcv was rather clean. But I cleaned it more just the same. I checked all the pipes and they are clean as well. No problems there. I also checked the in/outlets on the engine. Also clean. There was oil residue inside the manifold. Probably from the 13 years the car is old. I cleaned this as well. If you put everything together and let the engine warm up then it whines terribly. Pull the dip stick out or remove the oil cap and the whine is gone. That's why I was thinking of just riding for awhile with the hose which goes into the top of the head off. At least the whine is gone then. But obviously the pressure in the engine is reduced. I don't know if this would lead to other problems.

druid · Jul 19th, 2016, 11:54

Get a length of garden hose and use it like a stethoscope to pinpoint where the "wheee" comes from, i would look at the dipstick seal and the oil filler to start.
Should go without saying BUT be careful where you point it

LT South Africa · Jul 19th, 2016, 12:00

I went one better. I have a medical stethoscope. It seems the noise is between the vvt and the 2nd cylinder from the left. I took the plastic covers off for this and this is where it is more prominent. Very confusing. But, can I drive with the pcv pipe going to the top of the cams off for awhile?

Alex121 · Jul 19th, 2016, 12:18

I would see if you can get a manometer gauge and measure the pressure through the dipstick.

I'd also try and get a compression test done, if your PCV is fine I would now be looking at something wrong with the engine.

Jul 17th, 2016, 13:38	#1
LT South Africa Leonard SA Last Online: Sep 16th, 2016 05:24 Join Date: Jun 2016 Location: Lanseria	Whining noise in engine on low revs. PCV? Hi all. I have been struggling with the whining noise in the engine for some time. Posts here indicate it's the PCV. In summary. The engine has a terribly annoying noise at low revs. This is only when the vehicle reaches normal operating temperature. With the engine idling there is so much force on the oil cap that it cannot just be loosened and removed without a great deal of effort. When I extract the dip stick there is a distinct Pop as the pressure is released. And it pops back in against with ease as the pressure pulls it in. However, with either the oil cap off or the dip stick removed the noise is gone. I removed he PCV and found it was quite clean. But rinsed everything out including all the pipes. Whilst disassembled I cleaned the throttle control body as well. After reassembling I noted a huge amount of extra power. And the engine idles much smoother. However, the noise is still there. What do I stand to do next.

Jul 17th, 2016, 18:20	#2
skyship007 Premier Member Last Online: May 2nd, 2018 08:14 Join Date: Sep 2011 Location: DownSouth	Try changing the oil and oil filter. Make sure it's a major brand Xw40 (Acea A3/B4) AND use a real oil filter from a Volvo dealer (Or good Internet firm like Skandix), or one of the German TUV certified companies like Bosch or Mann. Check the fill level with the dipstick screwed in and avoid overfilling by using the correct amount of oil less a bit for the block. If that does not sort it, then check the valve covers are not loose etc. It might also be that the dipstick or filler cap oil seal are split. __________________ 2003 V40 1.9TD Mods: Scratches, bent bumpers, raised REAR mats & internal mud guards. SHELL ULTRA 5/40 & LIQUI MOLY CERATEC. Everyone should DYOR (Do Your Own Research) Last edited by skyship007; Jul 17th, 2016 at 18:26.

Jul 18th, 2016, 06:28	#4
LT South Africa Leonard SA Last Online: Sep 16th, 2016 05:24 Join Date: Jun 2016 Location: Lanseria	There is no harm in doing a filter and a oil change. I will give it a try. Trying to ascertain if hoses are collapsing will be difficult. But I will try. Seeing as the pressure is sucking and not pushing. I am seriously considering doing a little modification and installing a "T" connector on the top hose which runs past the oil cap and into the head with a inline filter just to keep just out of the system. Which should stop the noise. Will this work? Last edited by LT South Africa; Jul 18th, 2016 at 06:55.

Jul 19th, 2016, 09:57	#5
LT South Africa Leonard SA Last Online: Sep 16th, 2016 05:24 Join Date: Jun 2016 Location: Lanseria	Whining noise So I changed the oil filter and replaced the oil with a grade 40 synthetic. Excitedly I turned the motor and waited in anticipation for the engine to warm up. Not even 5 minutes and the noise is back at low revs. I run a driving school with this car and the noise is attracting a lot of attention from the examiner. I am in a rural town and about 200miles away from the nearest Volvo mechanic. As a temporary fix to the noise. Would it be okay f I loosen the pipe from the pcv which runs into the head under the plastic cover? Would this cause any engine damage?

Jul 19th, 2016, 11:54	#8
druid V40 Owner Last Online: Dec 13th, 2020 01:28 Join Date: Aug 2006 Location: Tonyrefail, Souh Wales. View Photos By: druid	Get a length of garden hose and use it like a stethoscope to pinpoint where the "wheee" comes from, i would look at the dipstick seal and the oil filler to start. Should go without saying BUT be careful where you point it __________________ *An MS Warior living one day at a time* "Neville" 207,000 so far. Water use 0 - oil negligible....

Jul 17th, 2016, 23:38	#3
canis Non Fragile Last Online: Oct 13th, 2023 05:46 Join Date: Apr 2010 Location: Chadderton, Oldham	You said "whining noise" - could it be that with that much suction going on, it's pulling the hose between the bottle and the manifold almost flat, causing it to rasp like a reed instrument? I'm sure it's not supposed to suck that much though.

Jul 19th, 2016, 11:34	#6
Alex121 Premier Member Last Online: Oct 27th, 2020 10:45 Join Date: Nov 2011 Location: -	If your PCV is blocked then it can push oil past the piston rings/valve stem seals (or turbo seals if you have one). Classic test to check it is to get into second or third gear when driving, accelerate up to 5,000 revs then let then engine brake to around 1000 revs, staying off the brakes, then go WOT throttle - Do you get any blue smoke out the pipes....If so, it's blocked!

Jul 19th, 2016, 11:48	#7
LT South Africa Leonard SA Last Online: Sep 16th, 2016 05:24 Join Date: Jun 2016 Location: Lanseria	Alex121 I had the pcv and all the pipes off on the weekend. The pcv was rather clean. But I cleaned it more just the same. I checked all the pipes and they are clean as well. No problems there. I also checked the in/outlets on the engine. Also clean. There was oil residue inside the manifold. Probably from the 13 years the car is old. I cleaned this as well. If you put everything together and let the engine warm up then it whines terribly. Pull the dip stick out or remove the oil cap and the whine is gone. That's why I was thinking of just riding for awhile with the hose which goes into the top of the head off. At least the whine is gone then. But obviously the pressure in the engine is reduced. I don't know if this would lead to other problems.

Jul 19th, 2016, 12:00	#9
LT South Africa Leonard SA Last Online: Sep 16th, 2016 05:24 Join Date: Jun 2016 Location: Lanseria	I went one better. I have a medical stethoscope. It seems the noise is between the vvt and the 2nd cylinder from the left. I took the plastic covers off for this and this is where it is more prominent. Very confusing. But, can I drive with the pcv pipe going to the top of the cams off for awhile?

Jul 19th, 2016, 12:18	#10
Alex121 Premier Member Last Online: Oct 27th, 2020 10:45 Join Date: Nov 2011 Location: -	I would see if you can get a manometer gauge and measure the pressure through the dipstick. I'd also try and get a compression test done, if your PCV is fine I would now be looking at something wrong with the engine. Last edited by Alex121; Jul 19th, 2016 at 12:21.

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