Tale of Woe - 3SGTE Gen2 troubleshooting

[senn]

Ok tech info Gen 2 3SGTE from an SW20 MR2.

I need to know -

Are these an interference motor?

Basically, the story is, was driving, noticed engine starting to drop a cylinder/run rough. While pulling into side street engine stopped. Now when i attempt to start it, it turns, but then seems to be stopped by something (valve? broken rod? Bolt from clutch/flywheel jamming in ring gear?)

in the week leading up to this, I had noticed it would occaisionly feel like it was running a little rough, but had thought it may be just due to old plugs/tired coil. It would always come good, so I had assumed an intermittant electrical issue..

Want to try as much basic trouble shooting before I look at pulling it down. If i can get it to spin, I can compression test it. Really hoping it's something simple, but i have that feeling in my gut....

[blakeg]

Take the dizzy cap off and getsomeone to turn it over by hand that will confim if its timing belt. If its stock internals it should be non interference. Does not sound good if it wont turn over

[senn]

should all be stock internals AFAIK.

It does turn over a little but then seems to stop, so it isn't seized. Knowing it should be non interference is good, makes me wonder if it isn't something else like shattered oil pump, dropped valve. Who knows maybe it ate a piece of turbo. I'll have a look at it when the weather is slightly nicer than it is this morning...

[senn]

Small update.

Oil - clean/clear - only 500km old, and looks it.

Coolant - Was toyota pink, now appears to be black/little sludgey??

Could this indicate BHG? Didn't receive any high temp readings last time the car ran? I would also normally expect if the HG has blown for the oil to be contaminated as well?

I can rotate the crank with a ring spanner, but it stops at a certain point. I don't like where this is headed heh. I'm out of time to deal with it for now. Pulling all the cam covers/intake etc off will have to wait.

To be continued...

[blakeg]

mebby somthing in the cooling system has died and seized the water pump ? hence no turning over ?

[senn]

mebby somthing in the cooling system has died and seized the water pump ? hence no turning over ?

I'd like to think that, but being as i can rotate the crank, and the cooling system has crud in it, I think it's gonna be unlikely. I'm hedging my bets on snapped rod or dropped valve. Are the water pumps on these driven by the cam belt? I honestly haven't had a chance to even look for the waterpump...

[blakeg]

yes they are

[senn]

Cheers, I'll bear that in mind when I'm trying to see what's stopping it rotating all the way next time. Would be good if it was just the waterpump + BHG, but god knows what the heat would have done to the head etc.

[jonathan yee]

So no smoke at all? Sounds similar to mine when bhg, never properly diag why it would rotate but jam when 2\3 pistons came to tdc. Guessing bent rods from hyd lock up.......? Still got bottom end here, should pull it apart one of these days.

[Moppitt]

Pull the plugs out and have a look at them/turn it over while they're out. If a foreign body got into the cylinder you'll see bits of it smashed on the plug (that will probably be missing), if its hydraulically locked then the shit will get blown out the spark plug hole as that cylinder comes upto TDC.

The crud in the cooling system definitely makes it sound like a BHG though.

[senn]

Good news. Looks like it WAS hydrolock. Engine seems to turn freely with all the plugs out but there is a fuckton of coolant in the chambers. eep. Will the coolant have damaged the rings etc? Obviously I won't know if the head is salvagable until it's removed. But progress, glad it didn't do a rod or drop a valve.

Should i drain the coolant? Put the plugs back in? I'll probably get it checked out properly to make sure it doesn't happen again anytime soon.

[Ken_T]

How long has it been like that? We did a rodeo once which had blown the gasket pretty bad or just driven with BHG until he no longer could manage. Mate who did the job said the cross-hatching on the bore was worn away. Well, when the job was done, the car had a misfire, it might have been from that, it might have been from the crappy gas system it had on it.

So yeah, get it fixed asap or don't drive it, drain the coolant, put marvel's mystery oil in the plug hole and let it sit until you can do the head gasket.

On a side note, the car sat in the front yard for a day before I took it to my mate's house and it that time, it had filled up the cylinder and had hydro-locked itself. Pull no. 4 plug out and cranked it to get the water out. It was hilarious watching a stream of water shoot out of the plug hole, hit the bonnet and cover the car sitting next to it.

[Moppitt]

The heads coming off to do the head gasket anyway isn't it? In that case you'll be draining the coolant for that job so you can do that now or later. No point in refilling it though, I wouldn't be driving it. As Ken said, you don't want leave it with water sitting in the cylinders.

(well, ok, I am driving a car that I think has blown a head gasket but I have a spare engine sitting on a stand, just waiting for the opportunity to go into my car but thats another matter )

Spark plugs... either or. You could put them back in and see if it will run but its probably not going to do it any favours so there is no point in it and as above, you don't want to leave coolant sitting in there.

Rings etc: couldn't tell you. I don't know what the loads are from being locked up like that. Sorry.

[lexsmaz]

Rings could be cracked from hydraulic locking, would depend on how worn the rings & ring lands are, etc .. I have seen Con Rods actually bent from being hydraulically locked, but from memory it happened at higher revs ( they drove through water ) ...

[senn]

I'm also wondering, because I have heard the gen2's have a nasty habit of doing this, is there anyway to reduce the risk of it occuring, ALA 7MGTE styles with ARP studs and a decent HG? This particular car is supposed to be my cheap(ish) runabout so I'm trying to make it as reliable as possible. Not interested in big power figures, just reliability.