S2 lost power funny exhaust noise, Help
- Thread starter jamieda
- Start date
PSH
PCGB Member
Hi Jamie
Sorry to hear of your woes... the guys have given some good input...i would add that don't start stripping the engine down before checking everything else first, you say it's not firing on number 2, so check all avenues relating to this first...check for spark, check for fuel, if you have both then compression would be next. I'm surprised that you say it's not lumpy, it certainly will be if only firing on 3 cylinders. You posted the video of the exhaust note which does sound as if only firing on 3...it may help to post a video of the engine as more can be told from the sounds coming from there. Considering that this happened after a day on the track then my suspicion would be the head gasket, certainly if it was a turbo.
If as suggested that you have dropped a valve or something I would expect noise from the engine...all I can hear is it firing on 3, no metallic sounds but then as stated we only have the exhaust video to go by. again if it was a turbo i would also suspect a burnt out valve but doubt this on an S2 model unless something is seriously wrong with the mixture. Regarding the oil leak, if I'm reading the picture correctly it looks like the back of the engine, again considering you were on a track before hand and also that you mentioned revs but now power to the wheels this would point to the rear crank seal leaking and contaminating the clutch, it may be that you have more than just the engine playing up. It's interesting that you say number 2?...this is not normally the cylinder where the head gasket fails, number 4 is the most common cylinder to fail although i will again state that i'm more familiar with the turbo model. Number 2 is however prone to the wrist pin failing due to oil starvation, especially after track use, there's a design flaw in the oil passageways that means that when driven and cornered hard on a track less oil gets to number 2 piston wrist pin and it will eventually fail, it certainly wears quicker. Your symptoms are not this though, not unless you have a rod sticking threw the side of the engine block..
To summarize check out as much as possible, if you have fuel and spark on all cylinders then you may have to start taking things apart, I would let a specialist look at it first though as it's difficult to find what's wrong if not obvious once it's all apart...good luck...
Pete
Sorry to hear of your woes... the guys have given some good input...i would add that don't start stripping the engine down before checking everything else first, you say it's not firing on number 2, so check all avenues relating to this first...check for spark, check for fuel, if you have both then compression would be next. I'm surprised that you say it's not lumpy, it certainly will be if only firing on 3 cylinders. You posted the video of the exhaust note which does sound as if only firing on 3...it may help to post a video of the engine as more can be told from the sounds coming from there. Considering that this happened after a day on the track then my suspicion would be the head gasket, certainly if it was a turbo.
If as suggested that you have dropped a valve or something I would expect noise from the engine...all I can hear is it firing on 3, no metallic sounds but then as stated we only have the exhaust video to go by. again if it was a turbo i would also suspect a burnt out valve but doubt this on an S2 model unless something is seriously wrong with the mixture. Regarding the oil leak, if I'm reading the picture correctly it looks like the back of the engine, again considering you were on a track before hand and also that you mentioned revs but now power to the wheels this would point to the rear crank seal leaking and contaminating the clutch, it may be that you have more than just the engine playing up. It's interesting that you say number 2?...this is not normally the cylinder where the head gasket fails, number 4 is the most common cylinder to fail although i will again state that i'm more familiar with the turbo model. Number 2 is however prone to the wrist pin failing due to oil starvation, especially after track use, there's a design flaw in the oil passageways that means that when driven and cornered hard on a track less oil gets to number 2 piston wrist pin and it will eventually fail, it certainly wears quicker. Your symptoms are not this though, not unless you have a rod sticking threw the side of the engine block..
To summarize check out as much as possible, if you have fuel and spark on all cylinders then you may have to start taking things apart, I would let a specialist look at it first though as it's difficult to find what's wrong if not obvious once it's all apart...good luck...
Pete
robwright
New member
Not quite that cut and dry. As the name suggests it will identify no or low compression but it is definitely a good staring point I think. Agree with Pete I don't see any compression woes that would cause your oil issue. If your finger nails aren't oily then it may be time to get it checked by your specialist. Especially in light of the amount of work you say has recently been done.
PSH
PCGB Member
I certainly can't hear anything metallic...but yes it's only firing on 3 but other than that it sounds ok......if it will idle or if you can get someone to hold it at a constant rpm you could take each HT lead off in turn, the one where there is no change in sound will be the one not firing so start with number 2, be careful though in case you have a broken HT lead as you don't want to get an electric jolt. Take the plug out and check that it sparks.... also that the plug itself hasn't failed...this can happen, especially with iridium plugs...i would expect the plug to be very wet, unless it's not getting fuel of course which will lead you in another direction. Rest the plug against the engine and turn over to check for spark, it's worth doing this for all cylinders as you can get a better understanding of what's going on from the state of the plugs.
Pete
Pete
PSH
PCGB Member
hmmm in those last two video's the engine doesn't sound as bad... I mean it sounds like all 4 are firing although perhaps missing a beat....when you opened the throttle though in the other video it had little pick up and was certainly missing. I would certainly check all basics before taking anything apart...
Pete
Pete
Fred Hindle
New member
It could be really simple and just be a failed plug. Try a spare plug in #2 and see it that makes any difference.
Cheers,
Cheers,
Monkeythree
New member
I wouldn't spend any more time with the engine running because if you have fuel but no spark in no.2 you will have put quite a volume of fuel into that cylinder by now which won't do your cylinder or oil any good. For any further troubleshooting on the ignition side, start by isolating the fuel pump so you are not washing the bores any more. You need to check which relay to pull to cut the fuel but still give you spark (might be the DME relay but not sure about this).
bmnelsc
New member
As per checking for fuel delivery to No 2 - can you pull injector from the manifold leaving it connected and put it into a jar or similar. Pull the coil wire and crank it to check for fuel delivery. I haven't fiddled with injectors/fuel rail on a 944 but running your injectors (one at a time) into a calibrated tube is described in the 924 (and several other makes) manuals to determine if your injectors are delivering sufficient volume. Might be worth a try.
Have you replaced the plug leads ? If so what with ? I would get a loan of a plug lead and try that. The leads on an S2can break at the right angle in top of the head. It's not always obvious until it snaps in half. I had that problem with mine when I bought it. It would run on 3 or 4 depending on how the lead was feeling that day. I only discovered it when I changed the leads as part of what I would normally change on a car I didn't know (plugs ,leads , fluids, filters, rotor arm etc.) . The car would run but just have no get up and go.
jamieda
New member
thats kind how it felt, just ran a compression test and all 4 cylinders showing 180 psi
inside the cylinder thats not firing is very wet compared to the others that are bone dry. (looked through the spark plug hole with a torch)
In answer to your question no i haven't changed the leads, changed everything else but not the leads, simply because i couldn't find anywhere local that had them in stock. going to order some now and see how i get on mid week if i have time.
if that doesn't work then its off to GT1 in Chertsey as really want to get it sorted for TIPEC Beaulieu weekend.
Fred Hindle
New member
http://www.eurocarparts.com/ecp/c/Porsche_944_2.5_1988/b/Bosch/p/Car-Parts/Engine-Parts/ignition1/ignition-lead
Maybe a good idea to change the rotor arm and the dizzy cap while you are about it unless they have been done recently.
Cheers,
Maybe a good idea to change the rotor arm and the dizzy cap while you are about it unless they have been done recently.
Cheers,
Posts made and opinions expressed are those of the individual forum members
Use of the Forum is subject to the Terms and Conditions
