I'm looking for advice in trying to determine what my next step should be in fixing my Toyota 4AC. The problems started while driving down the highway the engine started pinging and progressively got worse, just as I was able to pull over the engine lost power, died and as I stopped the rad cap spiggot blew right off the top tank. after a tow home I tried starting it with no luck, did a compression test. Cylinder # (1) 115lbs. # (2) 85lbs. # (3) 38lbs. # (4) 46lbs. I'm wondering if the head gasket is leaking between cylinders 3 and 4 ? and would throwing a new head gasket on bring this little beast back to life ? this is a low budget project but I'd like to keep it running if I can. here are some pics. advice would be greatly appreciated.





Pistons look decent for 193.000 miles.


Both side of the head gasket.

 

i dont know what to tell ya but if your that far already and you have 193k id rebuild it mine lost all compression in the 3rd and 4th cylinder and i ended up having to rebuild my whole bottom end. that was after i drove through a lake tho. id so go for a stock rebuild its will still be a cheap project your should be able to do it for around 300$ i dont see anything wrong by the pics and i dont this just a head gaskit would do that no start thing and act the way described. was there any metal in the oil pan?

 

Haven't checked the oil pan but I didn't notice any oil in the coolant or coolant in the oil, with those two low cylinders I was hoping to find a bad gasket between them then at least I could count on a bump in compression when I threw it back together, but since the gasket looks alright the low pressures must be valves or rings $$$ this vehicle is a winter beater so rebuilds are out of the question. hey if you can rebuild an engine for the kind of numbers you mentioned you should go into business ! at this point just the head gasket, fresh oil and coolant and an exhaust donut and a few other small bits is over a hundred bucks.

 

I'm still trying to wrap my head around why the rad cap spiggot blew off, what could build a sudden and abrupt pressure like that ?

 

Is your temp guage working? Sounds like you totally overheated and didn't know it.

The pix of your tear-down don't look bad.... This one is not too clear....

Was there white steam from your exhaust? My experience with "slow" headgasket breeches has coolant going into the cylinder and getting burned... see #3 cylinder here, washed nice and clean



If it overheated.... you know what you must do....

 

$300 for a rebuild is parts only, do it yourself, assuming you didn't warp the head. If you need to pay a machine shop to deck the block and head, it gets more expensive fast. Your pistons may actually be a bit too clean for the mileage of your engine, which could mean they've been steam cleaned by the coolant leaking in and burning, like misterzee mentioned.

 

I currently have a head out for cleaning, machining, valve adjustment and a full looker-over and its only runnin me $80.. not too terribly expensive.
Edit: Oh nevermind i just saw the "block and head" i was thinking just the head at first. Still tho you should send the head in while you got it off.

 

Yeah, it's not bad if you just need cleaning and looking over, but for a full rebuild kit (just the bottom end), it's easily $300-400, and probably close to that much again for the maching work if they do deck the block and head, and bore & hone. I guess it just all depends on what it needs.

 

Come to think of it I have noticed a smell of antifreeze lately, just faint but I never checked into it, has to be gushing I guess before my brain kicks in !!! lol.. no the car doesn't have an H2O guage just the factory guages which stopped working years ago, I never noticed any white smoke, the period of overheating was fairly brief, from when it started pinging maby 3 or 4 minutes before it started losing power then the rad blew it's top. I took a straight edge to the head and it's warped by 0.016in or 0.40mm. thats way over limit. looks like she's a parts car now, thanks for all your help guys !

 

I had that happen to my truck. the temp gauge was gone and my truck shut off at a stop light. luckely it was infont of walmart!..lol but as yall know them aluminum heads arent worth a durn and of course it worped. so i took it in a shop and hand it pressure tested and shaved. that swhat ya gotta do.

 

At Walmart? I didn't think walmart did anything but import cheap China products, oh and have scripts for $4.