(Hesitation + Missing) - Over Heated = Question

[kevsster]

Hey guys, after a day of having my RB25 S13 on the road, I overheated it to the point of shutting itself down, long story short, worst moment of my life, almost threw up/cried etc. Anyways, runs like crap. Did a compression test, cylinders were all pretty even and i dont trust my tester but they were about 120-130 across. Had a leak down test done, 1st, 2nd, 3rd, and 4th had small (as in barely any) leaks on the intake valves. The machanic said that he figured some oil/intake plenum residue melted and ashed onto my valves not letting them seat properly thus making them a bit leaky. Im running some intake cleaner through it right now as he recommended, but im wondering if you guys think there could be more damage done by the overheating. It has a very stumbly idle at around 600rpm, where before it was rock solid. When i get into it there is hesitation and missing. All the plugs look fine, and its not burning any oil or coolent. How suseptable to heat are the coil packs, maybe one or two arnt putting out the best spark? Maybe its the MAF crapping out? Really at a loss here guys, any help would be really appreciated,

Thx, Kev

[Eikon]

So can we ask you why you overheated the car?

Did you replace your water pump, check your thermostat, etc...

Oh well.. spilled milk I guess.

Yes.. coil packs fry pretty easy. I would expect you've ruined a couple at least.

How's your head gasket?

Sounds like you have a good excuse to tear it down and rebuild it the right way now.

Good luck!

[rb240det]

I've been lucky so far...only lost one coilpack in the 7-8months I've had my RB20. Don't know if that's the actual problem, but they're easy to get so you might want to check them.

[kevsster]

I wish this was a better story but its not. Here it is anyways...

Rewind to one week ago:

I thought my temp gauge was working....

I swapped in the ka sensor like your supposed to, it would warm up and hang around right in the middle. Which i guess is the end of its travel, because during the whole thing it never budged. Which is why it overheated in the first place. I was heading to work which is about a 15 minute drive from my house. Some highway driving which was fine, and then about 5 minutes through very busy and congested city traffic. I was cruising in the left lane of traffic towards a light. I stop and this is when i notice my car not running very well, it **** me" is what I said I believe. So here i am in the middle of traffic stopped at a light. I cant go right because theres a median, i cant go left cuz theres a line of traffic and i cant just turn my car off in the fast lane of the frigging highway. As I take off from the light theres a chorus of pinging, knocking, clattering. Got out of the left lane, pulled off the road and the car died as I was pulling into the parking lot which happend to be my work.

Anyways, needless to say the car was hot, it was smoking all over, smelt like death, I think I pretty much went into shock right before my 8hour shift (as a server ) over the whole thing. I felt like throwing up, like I said, it was brutal. 2 and a half months of work and a bunch of money, and I was sure it was all gone. After my shift I realized that the heater hose coming off the firewall was in two pieces, not split, but like someone cut it with an exacto knife right in half. It must of happend just as I was coming into town and then by the time I was at work the damage was done.

So fast forward a week, and head gasket is okay for now, I'm gonna watch it very closely for the next little while, no coolent on the plugs yet so its okay at the moment. I really would like to tear it down, but I dont really have a clean shop to do it in, plus the time/money/ability/ to do it properly. If the valves dont get any better with a couple tanks of the intake cleaner I think I will just have to sell this motor to someone and buy another.

Im definetly not giving up on the RB tho. I dont have to tell you guys how wicked a machine our cars are, and this wont stop me from doing it all over agian.

[Eikon]

wow... that sucks dude. At least you have a good attitude about it now.

You might try some seafoam in your gas tank, crank case, etc.. that might just break up some of the carbon on you piston or valves.

I've got a couple extra coil packs I can send you if you want to test them out. But, perhaps you can find some cheap on ebay or something.

Did you put a new water pump and thermostat on yet? I always ask because my first 6 months with my RB were a disaster because I didn't spend the extra $100 on a water pump. The fins were completely rusted away!!! So it would run for a bit at normal temp, but after any load at all it would start to overheat.

Anyhow... flush the coolant system, try pressurizing it to make sure you don't have leaks anywhere, then test and/or replace your coilpacks.

Hopefully things aren't as bad as you think they might be. RB's are pretty tough to blow up!

Good luck.. keep us updated, and feel free to ask lots of questions. Most of them I won't be able to help with, but there's a ton of smart folks on here who will jump in with some advice.

[kevsster]

Yah, i didnt change out the water pump either (My motor only had 67km on it tho), but i did put a brandnew $50 thermostat and it seems to be working just fine still. I had a quick look on ebay for coils and didnt come across any, i'd take you up on your offer unless you know of any usd coil replacement, Ive read the sticky but id doesnt really answer whether they are the Q45 or the VG packs that the RB's use.

If anyone can think of anything else I should be looking at, I'd really appreciate the input.

[skillzilla]

You can order Q45 coil packs (cyulinders 1 and 2) from any auto parts store, they usually run about 55-60 bux. Or, find someone that is selling them. I know a local shop here has some extra from aparts motor, if you want I can give you their info and see if they wanna ship them out. Or, if you trust me, paypal me the money and Ill send em to you. Your call I guess, if you end up not finding any. I can get them for $25 from the shop.

[kevsster]

That sounds pretty sweet, i'd really appreciate that. I guess I just want to know if anyone else thinks my coil packs could be the problem, or if theres someway to test if they've gone bad.

But if you could give me your email address I can send you my info and maybe paypal you the money if the shop decides to sell em. It would be nice to start collecting some cheap RB parts up here.

My email is [email protected]

thx

[skillzilla]

You can test your coilpacks by testing the resistance between the 1st and 2nd pins, if youre looking at the coil pack as it sits in the motor, they are the pins on the left and the middle. They should have between .7 and .9 between them.

Heat is a huge destroyer of coilpacks, I have had two go bad. As the heat rises, it raises the resistance in any electrical system, and can make coils not fire. This is a the same reason a lot of peeps run without the coil cover on their motors.

But ya, just LMK if you want to get some, Im sure he has more (prolly 3-4 Id guess). My email is [email protected] if you wanna work out the details.

[kevsster]

Yah that makes a lot of sense, I thought I could feel a difference from when its cold too when its warmed up so maybe there actually is a difference; if one is going bad, the hotter it gets the worse it'll get. I just didnt know how resistant to heat the packs were.

Oh, and I did actually wonder why most people ran without the cover, I thought I was missing some sweet JDM detail under there, lol.