Engine sounds bad when cold

[MJ]

Advice needed Since the car (1.7) had it's MOT, and an engine oil and filter change a couple weeks ago, its sounded bad when starting from cold. She runs fine, and I think she sounded aright when warm, although I didn't listen specifically.

I checked today, and it seemed ok as soon as it started, and then after maybe a minute of idling the funny noise starts. The engine sounds like a diesel engine. Quite rattly and has a sort of banging or splashing sound.

As the car wasn't serviced, just new oil and filter they shouldn't have changed or adjusted anything which would cause problems.

I've checked the oil level - fine, the oil looks nice and new and clean and I've checked the filter, it is a genuine Volvo one for b172's. We filled up with fuel after the MOT (Shell V Power as usual), don't know if that could be linked...

Here's a sound clip of the car. http://www.geocities.com/mj_racer_500/F ... sounds.mp3 The first part was recorded with the bonnet open, looking over the wing at it, the second part from the ground looking towards the front valance. Its not the best recording, but hopefully it'll help.

So what do you think? I have a couple vague ideas, but they're just guesses Thanks for any help

[classicswede]

the normal reason for this would be to thin a grade oil ( or just very poor quality) resulting in lack of oil pressure. As the 1.7 has solid lifters I would not have thought so.

Are you able to determin where from the engine the noise is coming?

[MJ]

I don't know what oil they used, as we still haven't had a bill come. Normally it says Castrol GTX 10W. We used to get a small top up bottle as well which was always Castrol GTX Magnatec 10w-40, but not been given one recently. Maybe I'll have a feel of the contents of one of the old ones, and compare it to the oil on the dipstick, see if one seems thicker.

If it was thin oil, how serious is it? Could the car be used a few times before being changed, or driven straight to the dealers, or not moved until fixed?

Not really able to tell where it's coming from. It might have been towards the front, by the cambelt, but I'm not sure. I didn't want to leave her running too long when she sounds a bit like a ford transit I can have an investigation again if it would help, but it's a bit tricky to tell. I'm not sure if it's all coming from the same place or not. The first time I head it, it sounded like splashing, and I thought maybe it was the crankshaft/con rods making the oil splash, which I guess would be more obvious if the oil was thinner, but that's probably entirely wrong...

Thanks for the suggestion. I did consider that it could be the wrong oil, but that seems such a simple thing to get wrong, and I'd assume they wouldn't use many different types to confuse anyway.

[Chris_C]

If it is oil, it'll go away after 5-10 mins, as the oil thins out with the temp. It's an old trick when you're selling a car to stick thin in to take away all the knocking If it is that, then odds are the valve clearances need looking at I'd guess. Fake sounds like a bag of bolts from cold

Thing is, I don't think that sounds that totally, I reckon I can hear something else. Don't ask me what... but... Any chance of a vid with bonnet up, with a bit longer running, say 15-30secs, from cold mate? Choke in so it's not flooding, but about 15/1700rpm.

[MJ]

From cold, but with choke in? What, hold it on the throttle to stop her stalling? I can do a vid like that, but maybe I'll wait a day or so, in case anyone else has ideas so I can do them all at once

So thin oil is supposed to take away the knocking? Well in that case it must be super thick She runs fine, and I think the noise must go away soon after driving off, but I'm not certain. If the bill doesn't come soon we'll have to phone up the dealer again and see where it is, and what oil it says was used.

The thing is, I noticed this sound the day after the MOT, and I've noticed it every time she's been out since (only a few times mind), but not before. It's just suddenly started, so it must have been something that day. Valve clearances wouldn't go wrong just like that would they?

Unless the mechanics revved her excessively and caused anything to happen...

[pettaw]

Techies normally put thicker oil in to stop rattles not thin and whatever people say about 'too thin' oil its all rubbish anyway, well, so far as the difference between a 15-40 and a 5-40. They're both the same when up to temperature. 10-30 might be a bit thin, but they're not recommended for use on any Volvos AFAIK so if you had a main dealer service it should have been correct. I use 0-40 in all my cars without problem. Its only a problem if you go racing all the time where you need a heavy grade to stand up to the extra abuse and high temperatures, something like a 10-60, but we're dragging off-topic here

It sounds to me like all the internals of the engine are knocking about. That sounds like a serious oil flow problem to me. Its difficult to hear in that short clip though, but I would say that it sounds a bit fast for valve noise. How quick does the oil pressure light go off when you start it?

I would, if you can, do another clip with the car first start in the morning. Take the clip from right before you turn the starter and then running the engine until the noise goes away.

Chris just means start it up and put the choke in a bit get the revs to about 1900-2000 to make sure its not over-rich and spluttering away. Hopefully you're doing that anyway

If it was running fine before then I would suggest the garage does an engine flush and then another oil and filter change.

[dalahare]

I've got 25w-60 in mine, it's gotten rid of my early morning diesel sounds.

[classicswede]

Without being abl;e to hear that clip properly one thing does stand out to me - The day after the MOT. Its quite possible the carb was adjusted for emissions and that could be causing to run lumpy and make funny sounds.

I know that may not be the case as you say it sounds like knocking. If you get a short peice of hose and put one end to your ear and the slowly move the other end around the engine you can often detect the general area the noise comes from - including air leak wistle.

[Chris_C]

Yup, Andy knows what I mean!

Hmm, Dai has a point about the emmisions thing... but I really wouldn't fiddle with that until sure tbh

[MJ]

Well I was with the guy when he did the emmision test. He asked me to come in to help. I revved it up to 2k, and let it drop to idle, then he stuck the thing up the exhaust pipe and got the reading. He didn't adjust anything. I've got the results printout here somewhere, but it passed fine.

Remember this engine has only done 33k miles, so it should still be young and sweet And it's never raced or abused

The hose as a stethoscope idea is a good one, I'm sure there's a bit about in the garage somewhere.

I think I'll ring up the dealer on Monday and ask what oil they did use. As for the oil pressure light, I haven't noticed it on, I assume it goes out immediately on starting, but I'll check that next start.

And I'll do a new video/sound clip. Video files are rather large, I could put it on Youtube, but I don't know how well the sound would come out... Maybe I'll put up the vid and a separate sound clip as well.

Thanks for all the ideas everyone

[Chris_C]

I can host if needed buddy.

[foggyjames]

It does sound a bit fast for something cam related, assuming that we're listening to 1200-1500rpm. Most likely bottom end. Thin oil does seem likely, given that it was shortly after a service.

Of course having said that, it'll probably prove to be something trivial after all our predictions of doom (or at least a hasty oil change!).

Also try pressing your ear to the end of a breaker bar (or similar) to trace noises.

cheers

James

[germ]

well, i let my dad hear it and this is what he thinks.

either the engine is very high millage or when they were changing the oil on the ramp letting the oil drip out somone drove it off and had a drive round, ....with no oil in it, they turned it off when it sounded bad and thought ohh shit no sump plug / oil quicly put the plug in and oil.

(ofcouse they would of reved it too...)

it's those youngsters jumping in and thinking its finished, happens quite alot, think amr

if the engine had of siezed they would of been shitting a bigger brick


i suggest you go moan ..lots about it.

Cheers
will

[MJ]

Right, I did a video yesterday from a cold start.

I tried to get sound from several angles, at both tick over (900 - 1000 rpm) and at higher revs (1700ish - 2000ish). I’ve just created a YouTube A/c to upload it, but it says it’s processing. I’ve no idea when It’ll be available. http://www.youtube.com/profile_videos?user=MJ5500

As you can hear, the engine sounds fine for just over a minute after starting, and then it gets noisy. I think at about 1 min 20, as the revs are held high for a few seconds. (The rattling sound just as I get out of the car is just the gearbox/clutch when I let the clutch pedal up to get out. After I got out, my dad got in and held it in to stop that noise. I think he released it part way through the video, as there was a couple strange rattles)

After the clip stops, I tried the hose thing for about four mins, whist the engine sounded the same. Then I dove round the block to warm her up a bit, and when I got back she sounded a fair bit better, but I'm not certain if she was perfect or not, It's hard to be so precise, but she was certainly better. The fan came on when I stopped, which seemed a bit quick for her to have got so hot, but I'm sure that's nothing.

Something else which I'm sure is nothing. After I got back and opened the bonnet, I noticed a tiny whiff of steam. On closer inspection, it came from the shield thing over the exhaust manifold, which collects hot air for the carb when it's cold. I expect that was just condensation that settled in it.



Andy, the oil light went out whilst the starter was turning, just before the engine fired.

Dai, I tried using a hose to hear where the sound was coming from, but it didn't work to well.

James, I did this before I read your breaker bar comment, so I haven’t tried that. Oh, and the previous recordings were done at tick over, with some choke, at about 950rpm ish, not 1200-1500rpm.

Will, The engines only 33k, so not high mileage. I went in to have a look under the car whilst it was on the ramps, and I'm fairly sure the oil was draining then. I didn’t see it again till it was in the MOT section. I would have thought it very unlikely considering this is a main dealer, and they weren't in a great rush that day, but anything is possible. I guess if everything else is ruled out, that maybe a possibility. Anyone here with a very high mileage 1.7 know if they sound like that? I guess there's no way to prove it without taking the engine apart, or perhaps finding a load of swarf on the drain plug.


And on the note of emissions results of the MOT, I have them here.

Mag timing offset -20.0

CO % vol 0.29
CO2 % vol 13.67
HC ppm vol 84
02 % vol 2.02
Labda 1.089



Anyway, I’m off to the dealers tomorrow to moan, and see if they have any ideas. :/

[foggyjames]

It doesn't sound that bad on the video. Tappets, perhaps? These kinda noises are tricky to diagnose remotely.

cheers

James