Engine: D5: - Popping noise from induction system

Nickthecook · Feb 16th, 2015, 21:05

Can anyone help please?

I have recently purchased a high mileage V70 D5 (185bhp) It has a slightly rough idle, but pulls like a train. There is a distinctive pop, pop, pop coming from the induction system. The air box seems to amplify the noise, so it's difficult to say where it's originating from. It is definitely in the induction somewhere though. It increases with revs up to about 1500, but then isn't really noticeable after that. It gets louder the hotter the engine gets and the other day it sounded like a blow from the exhaust. I've read many threads, regarding the wear on the hydraulic valve lifters on the early 185bhp's causing late closure of the inlet valves, resulting in blow back.

I intend to get it compression tested tomorrow. One thing that did occur to me, that doesn't seem to be mentioned anywhere. The D5 is a 5 cylinder unit and I've read that this configuration causes uneven crankcase pressure. Is it possible that the popping sound could be from pulses in the crankcase pressure, reverberating through the breather system. I have a little smoke coming from the oil filler, but not under any real pressure. Does anyone know of any part of the breather system, that could cause sudden pulses of air to enter the induction system? Other than the obvious exhaust gasses coming back through inlet. The inlet manifold is fairly quiet, the noise seems to originate around the engine side of the passenger footwell.

Changes to the level of the noise does not effect the idle speed. There is no excessive smoke from the exhaust. The car runs and drives like a dream.

I know it probably is the lifters and i'm happy enough to replace them if needed. The rest of the car is mint and it has an extensive service history. i haven't been able to find any posts from people who have done this and any out comes.

If anyone could throw a bit of light on the subject, i'd greatly appreciate the help. Thanks.

cheshired5 · Feb 16th, 2015, 21:52

Quote:

Originally Posted by Nickthecook

i haven't been able to find any posts from people who have done this and any out comes

http://www.volvoforums.org.uk/showthread.php?t=223589

Nickthecook · Feb 16th, 2015, 22:24

Thanks for the reply cheshired5

Just found this on youtube. http://youtu.be/q8CtUfU1Ico It's the same noise I've got coming from mine. Seen a few similar vids, but this guy claims it's the vacuum pump and does a good job of shutting it up. Car just seems to go to well for it to be valve blow back and not getting any errors.

chiptivo · Feb 17th, 2015, 14:24

Quote:

Originally Posted by Nickthecook

Thanks for the reply cheshired5

Just found this on youtube. http://youtu.be/q8CtUfU1Ico It's the same noise I've got coming from mine. Seen a few similar vids, but this guy claims it's the vacuum pump and does a good job of shutting it up. Car just seems to go to well for it to be valve blow back and not getting any errors.

Engine mounts - vacuum controlled.

Torsen · Feb 17th, 2015, 23:24

Mine is still popping after I change out vacuum engine mount. (One was leaking)
I tryed the trick i the video. No help.

Nickthecook · Feb 18th, 2015, 22:25

The burble, gurgle out of the filler cap was caused by two leaking bottom engine mounts. I just unplugged the feed to the 'T' junction in the vac line at the front of the engine and plugged it with golf T Peg. Burble, gurgle stopped. Then plugged back in the feed and tried each mount and found both were shot.

The pop, pop from the air box remained. If I rev the engine for a few seconds and let it idle, the noise goes for 10-15secs. As mine is an early EU4 and they're known for having hydraulic lifter wear, It looks like the noise is exhaust gases escaping past the inlet valves. Hoping it's just the lifters and that I won't need to replace the rockers aswell. I'm going to order the parts and then decide if I'm going to get my hands oily or send it to the garage. Had a look in the Haynes manual and I think I can handle it. Just need to ask a mate to make substitutes for the two Volvo tools needed.

Torsen · Feb 18th, 2015, 22:32

Nice. Dont forget this tread;-)

Nickthecook · Feb 21st, 2015, 12:26

Just to update. Tried wynns lifter treatment, no joy. Noise is present at start up, fades whilst warming up and returns when up to temp. I would imagine on warm up the oil is thick enough to hold the lifter, but too thin once up to temp. It's a 2005 EU4 engine, so was built at the time the faulty lifters were used. Definitely going to roll my sleaves up on this one. I've not sold my old car yet, so will use whilst the Volvo's off the road. That way there's no time limit imposed on the job. Does anybody know if the timing belt needs to be removed completely? It was only changed 20k ago. Is it possible to mark the belt on the inlet cam sprocket, take the tension off the belt and slide it off the cam sprocket? As long as the engine is set to T.D.C. and the cams are replaced in original position, I can't see a problem. I may be missing something though. Of course, the engine will be rotated by hand after the belts back on, to ensure everything lines up.

Simon Jones · Feb 21st, 2015, 13:57

My understanding is that cambelts should not be re-used as they contain glass fibre strands which get weakened once tension is removed and then re-applied.

D5meister · Feb 21st, 2015, 18:13

they are kevlar yellow aramid fibres these days and are v tough

Feb 16th, 2015, 21:05	#1
Nickthecook Newbie Last Online: Yesterday 22:21 Join Date: Feb 2015 Location: Newtown	Popping noise from induction system Can anyone help please? I have recently purchased a high mileage V70 D5 (185bhp) It has a slightly rough idle, but pulls like a train. There is a distinctive pop, pop, pop coming from the induction system. The air box seems to amplify the noise, so it's difficult to say where it's originating from. It is definitely in the induction somewhere though. It increases with revs up to about 1500, but then isn't really noticeable after that. It gets louder the hotter the engine gets and the other day it sounded like a blow from the exhaust. I've read many threads, regarding the wear on the hydraulic valve lifters on the early 185bhp's causing late closure of the inlet valves, resulting in blow back. I intend to get it compression tested tomorrow. One thing that did occur to me, that doesn't seem to be mentioned anywhere. The D5 is a 5 cylinder unit and I've read that this configuration causes uneven crankcase pressure. Is it possible that the popping sound could be from pulses in the crankcase pressure, reverberating through the breather system. I have a little smoke coming from the oil filler, but not under any real pressure. Does anyone know of any part of the breather system, that could cause sudden pulses of air to enter the induction system? Other than the obvious exhaust gasses coming back through inlet. The inlet manifold is fairly quiet, the noise seems to originate around the engine side of the passenger footwell. Changes to the level of the noise does not effect the idle speed. There is no excessive smoke from the exhaust. The car runs and drives like a dream. I know it probably is the lifters and i'm happy enough to replace them if needed. The rest of the car is mint and it has an extensive service history. i haven't been able to find any posts from people who have done this and any out comes. If anyone could throw a bit of light on the subject, i'd greatly appreciate the help. Thanks. Last edited by Nickthecook; Feb 16th, 2015 at 21:11.

Feb 16th, 2015, 22:24	#3
Nickthecook Newbie Last Online: Yesterday 22:21 Join Date: Feb 2015 Location: Newtown	Thanks for the reply cheshired5 Just found this on youtube. http://youtu.be/q8CtUfU1Ico It's the same noise I've got coming from mine. Seen a few similar vids, but this guy claims it's the vacuum pump and does a good job of shutting it up. Car just seems to go to well for it to be valve blow back and not getting any errors. Last edited by Nickthecook; Feb 16th, 2015 at 22:25. Reason: forgot link. Doh!

Feb 18th, 2015, 22:25	#6
Nickthecook Newbie Last Online: Yesterday 22:21 Join Date: Feb 2015 Location: Newtown	2 different noises. 2 different problems. The burble, gurgle out of the filler cap was caused by two leaking bottom engine mounts. I just unplugged the feed to the 'T' junction in the vac line at the front of the engine and plugged it with golf T Peg. Burble, gurgle stopped. Then plugged back in the feed and tried each mount and found both were shot. The pop, pop from the air box remained. If I rev the engine for a few seconds and let it idle, the noise goes for 10-15secs. As mine is an early EU4 and they're known for having hydraulic lifter wear, It looks like the noise is exhaust gases escaping past the inlet valves. Hoping it's just the lifters and that I won't need to replace the rockers aswell. I'm going to order the parts and then decide if I'm going to get my hands oily or send it to the garage. Had a look in the Haynes manual and I think I can handle it. Just need to ask a mate to make substitutes for the two Volvo tools needed.

Feb 21st, 2015, 12:26	#8
Nickthecook Newbie Last Online: Yesterday 22:21 Join Date: Feb 2015 Location: Newtown	Do I need to fully remove the timing belt for this job? Just to update. Tried wynns lifter treatment, no joy. Noise is present at start up, fades whilst warming up and returns when up to temp. I would imagine on warm up the oil is thick enough to hold the lifter, but too thin once up to temp. It's a 2005 EU4 engine, so was built at the time the faulty lifters were used. Definitely going to roll my sleaves up on this one. I've not sold my old car yet, so will use whilst the Volvo's off the road. That way there's no time limit imposed on the job. Does anybody know if the timing belt needs to be removed completely? It was only changed 20k ago. Is it possible to mark the belt on the inlet cam sprocket, take the tension off the belt and slide it off the cam sprocket? As long as the engine is set to T.D.C. and the cams are replaced in original position, I can't see a problem. I may be missing something though. Of course, the engine will be rotated by hand after the belts back on, to ensure everything lines up.

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Feb 17th, 2015, 23:24	#5
Torsen New Member Last Online: Mar 6th, 2015 06:08 Join Date: Oct 2013 Location: Oslo	Mine is still popping after I change out vacuum engine mount. (One was leaking) I tryed the trick i the video. No help.

Feb 18th, 2015, 22:32	#7
Torsen New Member Last Online: Mar 6th, 2015 06:08 Join Date: Oct 2013 Location: Oslo	Nice. Dont forget this tread;-)

Feb 21st, 2015, 13:57	#9
Simon Jones Premier Member Last Online: Jan 15th, 2022 11:23 Join Date: Feb 2009 Location: Salisbury (ish)	My understanding is that cambelts should not be re-used as they contain glass fibre strands which get weakened once tension is removed and then re-applied.

Feb 21st, 2015, 18:13	#10
D5meister Premier Member Last Online: Feb 10th, 2024 19:13 Join Date: Nov 2008 Location: Huntingdon	they are kevlar yellow aramid fibres these days and are v tough

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