loud rattling/marbling under valve cover on SOHC KA. guides look fine & Searched

[sileightysomeday]

Ok, so I was driving my car from Jacksonville, FL to Orlando. which is roughly 160 miles. and on my way home i started to hear this rattling, at first it wasn't that loud and i thought it was my airbox hittle the frame, then i got home and noticed it was coming from under the valve cover. So I opened up the valve cover and looked at the head, everything seems fine. I did a search and checked the right chain guide and it looked fine. Ideally I would like to start the car with the valve cover off to see where its' coming from, but obviously I can't do that cuz I don't want to be covered in oil. anyway, so at idle it sounds like there are marbles or metal pieces rattling around in the head, then i rev it up and it sounds like a chainsaw with a dull chain grinding against metal and the rattling stops. I keep thinking it is the chain guide but I'd like a second opinion. there was a great article that i found here that said the guy drove like 50k miles with it like this and was fine. So what do you all think? the car is a '90 SOHC stock KA. is it safe to drive ? or should I avoid it? thanks in advance.

[kurama240sx]

hmm

my dohc and my brother sohc made that sound. It was a bad bearing, someone correct my if im wrong. If you dont replace it eventually it will get worse and ruin the engine and make it impossible to rebuild

....lol both engines were ruined

[neverlift]

you the guy they(local forum guys) were talking about from saturday night?lol

its not a manifold bolt is it? they tend to back out after hard runs long trips..(my old sohc had 4 that always came out after playing )is it knock(bb's in a can)?

[DaydreamDrifter]

I bet it is yout chain slapping against your front engine cover right along the water passage to the the water pump. After XXX miles your driver's side chain guide will disentigrate . Take the valve cover off and see how ,much play you have on the drivers side of the lower timing chain. If this is the problem, you need to fix this asap or the chain may jump and cause bent valves which could add another 200+ dollars to a do-it-yourself job. Also you may need toremove the oil pan to remove debris and plastic chuncks before they destroy the motor.

[LayNLow240]

Steel is a harder metal than alum is in all cases. so infact the chain will rub a hole into the water gallery. THEN you will have a big problem. that would require either finding a welder to weld the hole up (cast metals arent easy to weld as regular non cast items.) or the safest bet would be to get a new head.

[240sxmech]

check your lifters might if your chain is tight then thats what it will be

[Soravia]

Sound like it will be a lot of work. If you have to rebuild, why not get a good KA24DE dumped by SR20 swaps and redo things on it. Same work with better results and maybe less money.

[somedude]

lifters and timing chain arent that bad

[LessRice]

huh... this just happened to me last week thought it was the lifters... ... thought it was the timing chain tensioner... ... my motor blew two days ago and i tore the motor apart broken wrist pin/cracked piston and now my kouki has spent the past couple of days immobilized... its hard to tell without hearing the sound... i pray to god that you dont have the same problem

[sileightysomeday]

Well I diagnosed the problem: I was looking at the chain guide and it looked fine, so i manually turned the crank. as I was turning a bearing came flying out of the engine bay, I've traced it back to the A/C compressor tensioner pulley. when i turned the car on, the A/C belt was slipping which leads me to believe theres a bearing missing in the compressor tensioner pulley. when I give it gas, the compressor no longer slips but then makes a horrible screeching noise. SO, I've concluded that I just need a new tensioner pulley. Thanks for all the help guys.