Cracked head low compression on cyl 3 2.7 distributor type

I have a decision to make and could use some opinions. My truck is a 1995 Tacoma 4x4 2.7ltr with 203k. I bought it a year ago and have put 4k on it since. Since I bought it I have had an issue with cyl #3 miss-firing and have changed it 3 times. Each time it fixes the prob for a little while. Lately I have smelled antifreeze but found no signs of water in the oil, but last week it died on me and would not start. I pulled it to the mechanic and we got it started by feathering the throttle. It would run at higher rpm but would not idle. Throughout the day we checked sensors and ignition system. We checked compression and although the numbers were high compared to what I have seen still #3 was 25 psi. lower than the rest 155psi. We squirted oil in #3 and compression came up. After we did a pressure test and found a definite leak in the coolant system, I tore it down and found a cracked head between the valves on cyl.3. My question is could this cracked head show low compression on that cylinder? If so, after we put oil in that cyl. would the compression go up if the head is bad? And last, could this cracked head be the reason that it died on me? Any help is much appreciated. I am a musician with a limited budget so I am doing the work myself. Head? or replace the motor? Thanks ya'll

 

cracked head? that's your problem. nothing else. it's done for. replace it. youll need a new head set and head bolts to go with it

remove intake manifold and see how many intake ports you have. 8 round ports, or 4 double wide ports. do as little as possible to find that information. you don't want to lose any nuts or bolts. (remove intake boot and shine flashlight into throttle body to maybe see ports?)

order a head preferably complete with cams and chains.

once you get the correct head, proceed to replace it according to your manual.

its fairly easy on the 4 cyl since you don't really have a plenum or a bunch of wiring and hoses like a 6 cyl does.

so long as you have the head and its gasket correctly installed, timing set, bolts torqued properly, and are getting proper compression, you can have a mobile mechanic come take a look at your truck to fix the rest if you want. that should just be ignition and maybe valve clearances.

once everything is running again, return old head for core value.

 

Thank you very much for your help. I will go with the reman head. Found one @ Cylinder Head Int. and called, they seemed pretty helpful. I have block and pistons cleaned, timed and ready. Again thanks!

 

A place to comparison shop if you haven't already ordered. http://www.cylinder-heads.com/

 

Seems to me, that if the compression went up (how high?) when you squirted some oil into #3 cylinder, that means the rings are bad in that cylinder. If you are replacing the head anyway, you might as well replace the rings (or just replace the motor).

 

Wanted to take a minute and thank all of you. With your help I am back on the road literally. She started right up and it almost scared me. Again thanks folks!!!!

 

Another question if ya'll have some input. I had to change the harmonic balance pulley, it had slip and timing mark was off. Getting the bolt out was a bear. When I put it back on I used an air impact. I know the torque should be around 190 ft.lbs but I do not have the tool to hold the crack. Think it will hold?

 

Not something to guess with. Either pony up for a beam type torque wrench or call a couple of shops and see how much they'd charge to torque it for you.

If you don't have a torque wrench, how did you do the head bolts properly?

 

x2?

 

I do have a torque wrench but it only goes up to 80 ft. lbs. Think I will take it to Toyota and have it torqued. Again thanks for all the help!

 

You can buy a wrench for way less than a dealer will charge. If you can install a head, this is easy peasy.

 

here. put on a glove, wrap one of your belts around just the harmonic balancer, squeeze the belt tight against the harmonic balancer, and hit it some more with the air gun.

 

essentially youre doing what this guy is doing but without a bar. but if you have a strap wrench, even better!

 

@Music Yota

Every bolt on a vehicle has a torque spec. Most of us ignore the vast majority of them, learning about 'feel' over the years, learning by breaking things, learning by having things come undone.

There are certain things, like engine internals and this crank bolt that a torque wrench should be used for accuracy.

If you don't want to buy a torque wrench capable of doing this bolt, find a shop to do it for you. If they want more than $10-15, move along. Tip the tech a five spot.

After all your work/investment in new parts, you'll appreciate having this final bit done right.

I recommend Locktite blue on the threads too. NOT locktite red, unless you want to use a torch and heavy praying to remove it in the future.

 

Again thanks Toyota team. Engine has been running good after head replacement and have put over 400 miles on it. Lately it has been coughing a bit when I take off at a stop light. Yesterday It died but started back up. It got me home but was missing more frequently even at cruise speed and acceleration at times. When I shut it off it gurgled almost like it was hot but the gauge did not show it. It was slow to restart and missed more frequently. Today I started it and when it reached temp I the miss returned. (Note **) Even before the head change I was starting to have this prob. So far I have replaced the ignition igniter and still have same prob. Crankshaft position switch next?

 

Hmmm, this is a good one. I'll have to think about this one a little bit.
Regardless, great job on replacing your head and getting that squared away. I love hearing a good success story on a bigger repair like this. Bill gives good advice on the blue loc-tite and proper torque spec. There are certain places I'll trust my feel, as he states, but others I know to follow the spec. This crank bolt is one of those, I'd feel safe if I knew I could get above the torque spec by feel, but I have no idea what 200 ft lbs of torque 'feels' like. So I do this one with a torque wrench, or you can take it somewhere and it should be quick 20 bucks for them.

 

Once again I would like to share my current situation with the Toyota team and get some thoughts. After changing out the cracked head (which seems to be fine) I have been witnessing a miss after the engine reaches temp. This was the same issue that helped me find the cracked head in the first place. All sensors and such seem to check fine but I have replaced several things looking for the prob. The miss gets worse the longer I run the truck. Also, it will not take fuel quickly. If I stomp the pedal the engine will die. What I have replaced so far: Igniter, Dist cap, wires, plugs, temp control sensor, crankshaft position sensor, and maf sensor. (not necessarily in that order) While I had the truck tore down I replaced the fuel filter and seem to have plenty of fuel pressure. I have taken the ECM out and checked for ugly connections but at a loss of how to have it checked properly. The only other suspicion I have is possibly the Distributor itself. This is getting expensive, but I have became pretty efficient as a toyota 2.7l wrench man. Any thoughts?

 

Thanks for your reply. I did have a gurgle but gave it a good burping and have not heard it since. It has not lost any water and the oil shows no signs of water so far. The plugs are also burning clean with no residue. The weird thing about this miss is that it did not start until I had driven it 300mi + after replacing the head. Got me stumped