Help a noob out! Please?

[thowes24]

Hey guys, I found a 325i yesterday for $600 that I'm interested in purchasing. The only problem that I know of with the car is a broken rocker arm on cylinder 5 (It might be on cylinder 6, I can't remember.) The owner told me it was the result of a broken timing belt. When the belt broke, she pulled of the road because she knew what had happened from a previous experience with another car. The timing belt has already been replaced.

So, I'm wondering:
1. What damage could the engine have sustained from the timing belt/rocker arm? Maybe a bent valve, push rod?

2. How difficult is it to replace the rocker arm? I've searched, but with little luck. I've been getting mixed answers, some say that the head has to be removed to replace the arm while others say that you can just remove the rocker shaft. (Are there any guides on how to replace a rocker arm?)

3. Would it be okay to just replace the broken rocker arm and leave the others alone, or should I replace all 12 at the same time? Are there any other parts I should replace at the same time?

Thanks in advance!

P.S. I'm new to E30s and car maintenance in general, so go easy on me! (However, my grandfather is very knowledgeable with cars and he has a lift and most of the tools I would need.)

[shiboujin]

Long story short, it more than likely isn't worth it. Now, if you want to do a motor swap, you have a great candidate.

[thowes24]

Thanks for the quick reply!

Can you elaborate though? What kind of damage do you think the engine sustained?

[shiboujin]

Well, M20s don't have push rods. That's more of an American V8 thing.

regardless, if things went really well, you can replace the rocker and timing belt and be merry. To confirm it's ok though, you should do a leak down test and compression test. look them up to learn how to do them. Leak downs require an air compressor but will be the most telling.

Light damage will just be the rocker. But you could have bent valves and that will just make the engine run like ass. Or, the bent valve could have destroyed the valve seat, potentially wrecking the head. Even worse, you could have pitting in your pistons that lead to hot spotting and eventually melting a piston. that is, if there isn't already a hole in the piston.

summation:
Timing belts snapping can be anywhere from an easy fix to a trashed engine. I've seen very few that are ok though. A leak down and compression check will give you definitive answers without having to take apart the engine.

[thowes24]

Wow! Thanks for the advice man! I really appreciate it! I'll definitely look into that. :)

[StereoInstaller1]

That is the whole problem with interference motors, no matter the brand. That piston comes up, the valve is open: SMACK!

When it hits, it can pop a hole in the piston, bend the valve, bend the rod...or you might get lucky and only break the rocker arm.

Since this rocker arm is broken, I am gonna say that is actually good news. Think about it like this: breaking that rocker arm means most of the energy went into snapping that arm, rather than bashing a hole in the piston.

IMO, if it is the car you want otherwise, buy it. Pull the head and look for piston damage. Take the head apart and look to see if it is salvageable, then do what you have to do.

HTH,
Luke

[xwill112x]

when i snapped the timing belt in my vert, the rocker arms were broken like 4 of them? and the valves were trash as well. pull the m20, swap another one in, good to go.

[thowes24]

Is there any way that I can just look at the engine without completely removing the head to see if any damage was done to the valves, etc? When the owner pulled the valve cover, everything looked normal other than the rocker arm that was broken. I'm on a high school budget, so I'm not able to just buy the car and then put another engine into it.

[Dermeister3]

If your on a high school budget, i would keep looking. with the money you'll be putting into fixing this could be more than its worth to you. im sure you can find a better E30 that at least runs for 1200ish. i was on the high school budget before. now im on the college budget, and i think its worse.... lol

[xwill112x]

i was in highschool and bought 3 e30's my self, all funded by washing dishes. i know how it is.

[thowes24]

Yeah, and unfortunately, I don't have time for a steady job due to sports, ap/honors classes, beta club, fbla, and baby sitting for my sister, so my only source of income is random jobs that pop up when I have time and my allowance for doing yard work. :/

[gearheadE30]

^^ been there before. I'm a freshman at Purdue, so I went through that pretty recently, hah. Luckily my parents were pretty supportive of the hobby, I think perhaps because it kept me busy and out of trouble and such. I did the sports/too many AP classes/extracurriculars too. If this otherwise a clean, nice car and you can possibly solicit some support from your parents, you may be able to find a good junkyard M20 and have a nice car...

[thowes24]

My parents are very supportive, they just want me to stay focused.

And that's really what I'm looking to do. I was just going through the FS section and found an M20 for $150, so I'm still hopeful. Hopefully I'll be able to stop by a local independent BMW shop today and ask some questions and see if he's got an M20 in stock.

[StereoInstaller1]

Unless you have access to a boroscope you aren't gonna see shit.

A good idea might be to do a compression test, see if that cylinder has compression. If it hits 150ish, you will likely be OK just swapping that rocker arm.

[TS323]

id say if its the car you want/like and everything else about it is nice (no rust, interior is decent, straight body) then get it. m20 arent that hard to find parts for.