Forrest 35 Report post Posted October 3, 2009 (edited) PFL E30 325i So track day yesterday. Long story short, came in after a run with smoke pouring out under the bonnet after coolant spraying over the rocker cover, thought it was just the overflow hose leaking excess onto the engine, so let it cool down and went back out. Went out again looked down at the speedo and noticed the water temp at 3/4 and the battery light on, thought oh f**k! came back in and had lost the fan belt so no water pump pumping, no fan spinning or no battery charging etc etc. Fixed the belt, now when it is idling it sounds like there is a deep knocking inside, I can hear it knocking off beat and when blipping on down shifts it is very rattly and raspy not the usual deep blip. Anyone got any ideas? Looks like a motor rebuild could be a even closer possibility, it still drives fine, was noting it was lacking power on the other similarly tuned 325i's yesterday. Motor has down 306k. Cam needs to be replaced, I already new that, so I was already calculating a head rebuild. Any help is appreciated. Cheers, Nathan Edited October 3, 2009 by Forrest Quote Share this post Link to post Share on other sites
e30plz 1 Report post Posted October 3, 2009 My plastic bit that goes around the fan is quite loose from "fanbelt issues", Which makes a knocking sound as the fan hits it - Checked that? Might not be serious.. Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted October 3, 2009 ^ Nah this is inside the motor, I have already checked that. Quote Share this post Link to post Share on other sites
e30plz 1 Report post Posted October 3, 2009 Sweet just thought i'd say. Knocking in the engine doesn't sound too good Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted October 3, 2009 (edited) Have I broken something? Short answer Nathan Yes you have... rebuild time Edited October 3, 2009 by *Glenn* Quote Share this post Link to post Share on other sites
mark247 38 Report post Posted October 4, 2009 Time for m50 conversion huh? Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted October 4, 2009 Have I broken something? Short answer Nathan Yes you have... rebuild time Oh f**k. Well that is fantastic news! Thanks though Glenn Quote Share this post Link to post Share on other sites
e30plz 1 Report post Posted October 4, 2009 Short answer Nathan Yes you have... rebuild M52B28 time Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted October 4, 2009 I am not going to totally jump to conclusions yet, I can still drive it and luckily I won't be on the track till early next year, but I don't think the track day made it run any better Quote Share this post Link to post Share on other sites
antil33t 90 Report post Posted October 4, 2009 I am not going to totally jump to conclusions yet, I can still drive it and luckily I won't be on the track till early next year, but I don't think the track day made it run any better All I can see is "I want an M52B28" BL dude gotta hate it when your car does something you don't want. Quote Share this post Link to post Share on other sites
mark247 38 Report post Posted October 4, 2009 All I can see is "I want an M52B28" M50 bro, m52 are a lot more money for not much more engine really. Bad luck Nathan Quote Share this post Link to post Share on other sites
antil33t 90 Report post Posted October 4, 2009 M50 bro, m52 are a lot more money for not much more engine really. Bad luck Nathan Good to know man, Is there a 2.8 M50? Quote Share this post Link to post Share on other sites
mark247 38 Report post Posted October 4, 2009 Good to know man, Is there a 2.8 M50? Nah, just 2.0 and 2.5 non vanos and vanos. Non-vanos is where it is at, rough idle ftw. Quote Share this post Link to post Share on other sites
Guest FrantiC Report post Posted October 4, 2009 Have you checked under the valve cover? Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted October 4, 2009 ^ Not yet, a knowledgable friend has said you may want to check I havn't broken a rocker. That will be the next thing. Quote Share this post Link to post Share on other sites
bmpower 3 Report post Posted October 4, 2009 Gutted to hear that Nath - even though its not much consolation, your car looked pretty good out on the track yesterday, especially that alpina front in the rear view mirror!! Hope she's all good! And proof that you always need a 32mm spanner even with no viscous!! Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted October 4, 2009 ^ Cheers Kerry, pm me your email, I have some sick photos of me you and Oli in the same shot. And I am sure you have some for me. Haha and thanks, I mean I wasn't as fast as you, but atleast it looked good Quote Share this post Link to post Share on other sites
dirtydoogle 383 Report post Posted October 4, 2009 ^ Not yet, a knowledgable friend has said you may want to check I havn't broken a rocker. That will be the next thing.I was going to suggest that. I broke a rocker in my e24 m20b25 tank a few years back. It was rather noisy and really didn't like me afterwards....stuffed the cam too. Quote Share this post Link to post Share on other sites
bmpower 3 Report post Posted October 4, 2009 ^ Cheers Kerry, pm me your email, I have some sick photos of me you and Oli in the same shot. And I am sure you have some for me. Haha and thanks, I mean I wasn't as fast as you, but atleast it looked good pm'd, oh sweet post a couple on here too...!! you weren't slow though!! don't forget the secret headlight 10kw gain i have!! lol yesterday was definatly the best day i have ever had up there, today i did some mean drifts, not alot of staying in a straight line! Oh and they called it off after a 911 turbo lost it on the straight when the turbo kicked in ...thats what happens when you put the engine in the wrong place and strap on a hairdryer though.... Quote Share this post Link to post Share on other sites
RyanG 0 Report post Posted October 4, 2009 M50 bro, m52 are a lot more money for not much more engine really. Bad luck Nathan But m52 are superior!Good to know man, Is there a 2.8 M50?You can always stick a m52 crank in an m50. Quote Share this post Link to post Share on other sites
the stig 0 Report post Posted October 4, 2009 Happened to me last year, broken rocker. Still able to drive it but not much power and knocks Quote Share this post Link to post Share on other sites
Guest FrantiC Report post Posted October 4, 2009 (edited) Yeah you would kinda be surpised how the knocks can sounds bottem end but they are top end. When the machine shop messed up my head and didnt put the lock tab for the rocker arms, caused the intake side to spin and pop all the retainer clips off all the rocker arms shifted to the side and where barely touching the cam lobes, and the other side was in contact with the spring retainer, not the actual valve top. Made insane knocking noises which I thought where bottem end and it was lacking power hardout.. big suprise when I pulled my valve cover off though, I tell ya! Lucky I didn't run it too long and sorted that out easily without breaking any rocker arms or anything. Edited October 4, 2009 by FrantiC Quote Share this post Link to post Share on other sites
Steve K-B 51 Report post Posted October 4, 2009 Id also do a commpression test awell as pressurising the cooling system. Not sure how much water you lost (and where from?) but is worth doing as its an easy check. Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted October 4, 2009 Nathan...the reason I gave a short answer was I didn't have time to post up a story. First of all, check where the noise is actualy coming from. Use a stethescope and determine the location of the noise first before you start pulling it appart. If its a broken rocker, it will only be running on five cylinders. Then do a cylinder leak test which is better than a compression test when determining engine condition. If the fault is in the cylinder head, its going to have to come off. If its in the bottom end, the head will still need to come off. Finding the location of the noise first is going to help you find the actual fault without trying to have to guess. I have worked on this car previously and I know the camshaft is worn, from memory the lobes on no 2 cylinder are the worst worn. It may have dropped a slipper of one of the rocker arms, however the cylinder head would have to come off to do this properly. The engine has done 300+K now, it would be unwise to refresh the cylinder head without doing something with the bottom end as well. That is why Dan purchased the parts to do the 2.8 conversion, in preperation to do a rebuild. The knock from a worn camshaft is a deeper noise than tappet noise and can be confused with being a noise from the bottom end. As I said before, check and locate where the noise is coming from first before pulling things appart. 90% of repairing something properly is diagnosing the actual fault first. Pulling things appart trying to find the fault can be quite disheartning. While its still running you have a better opportunity to get your diagnosis right. Once you have determined where the noise is coming from, run the engine at a speed the noise is more previlant and then disconnect the spark plug lead on that cylinder and see if the noise goes. Its possible that the overheating caused a piston to pick up in the bore or its run a big end bearing. I'd also remove all the drive belts and run it as well just to make sure the noise is coming from the engine. The water pump might have collapsed a bearing. We had a M43 do this last week and the noise was very similar to a big end bearing knock. If you dont have a stethescope.. go buy one , theyre cheap as and a very handy tool to have. BTW: I'd refrain from driving the car till I at least knew what was going on...you might do alot more damage to the engine. If you want anymore help...feel free to give me a call Quote Share this post Link to post Share on other sites
Forrest 35 Report post Posted October 4, 2009 ^ Thanks Glenn, I really appreciate it. Also thanks to everyone else above for adding their input. I will keep everyone posted. Quote Share this post Link to post Share on other sites
