Cracked cylinder: is my engine done for?

Hello Tacoma lovers. My 2006 has been diagnosed with having a cracked cylinder by my mechanic. He is well respected and trusted. I was loosing small amounts of oil over a 2 year period. Nothing under the truck, none visible in exhaust. As time passed I would add a small amount to maintain some on the dipstick. This past summer while driving, my truck began shaking and my engine light came on for the first time. I pulled into a auto parts store and checked the computer out. Misfire on plug #4. Changed this out myself with success. A few weeks later the same shaking began again. Went to see my guy and he recommended new plugs and coils. This is the first time they had shown any reason to replace in 175k. He replaced and drove her to test for issues. No issues. I got in and fired her up and the shaking began and engine light came on. He kept her for a deeper diagnosis. Oil had been leaking into the cylinder closest to the drivers side rear. Not sure which number that is. This was causing the plug misfire. Sure I could put in a new engine, but is this the only route to take? What are the side effects if I keep driving? When I try to maintain a speed, my engine will shake the teeth out your head. If I give more peddle pressure it stops. Cruise control is a No-No. shaking is horrible. Idle is 1,600rpm. No other present issues with the truck.

 

Being an 06 with no other issues, it may be worth your trouble to find a Jasper or other remanufactured/overhauled engine. Last I heard, they were typically about $2-3K and took about a day to swap out. Then you should be good to go for another 175K mi, if not a quarter of a million.

 

Welcome to The Forum!

 

https://www.jasperengines.com

 

Cracked cylinder? not sure how you would make that diagnosis it could also be the head gasket I believe the 2006 had an issue with blown head gaskets.
I had a Dodge that would blow head gaskets and it does all those things you describe.

 

Could be a cracked cylinder wall that's leaking coolant into the cylinder or possibly a cracked valve seat in the cylinder head

 

once again it seems unlikely that the cylinder wall is cracked, unless you are running nitrous and over pressurize the cylinder. I also have blown a hole in the Toyota 3.0 but it was when the rod snapped there was no driving that one...
unless they actually flo test the block there is no real way to diagnose a cracked block/cylinder, even with a bore-a-scope it would not be easily found.
so once again I ask how to you diagnose a cracked cylinder with out tearing down the entire motor?

 

Welcome aboard

 

On an recip aircraft engine we pull an upper plug, turn the crank to bring a piston to a specified position (usually BDC) install a air inlet with pressure gauge into the plug hole, and pressurize the cylinder to about 80 psi. We then shut off the air and measure pressure loss in one minute. Dependent upon the engine manufacturer manual, typically anything over 75, that is, 5psig or less loss is considered good, and anything under 70 (10psig loss) is cause for tear down. A crack could be diagnosed via this method provided an average was obtained for the other cylinders.

 

At the same time, a blown head gasket could be found as well using the same method. A soap solution applied to the head and valve area while under pressure would be indicative.

 

Lift it too

 

Hard to say a cracked cylinder without tearing it apart

 

Yeah a leak-down test would determine a bad cylinder but would not diagnose a cracked block/cylinder it would just tell you that you have a problem with that cylinder: bad valve, cracked piston, bad rings, head gasket etc..
it just seems to me that a cracked cylinder wall would be the last conclusion I would jump to... I am just wondering how the OP's mech came to that determination..

 

Ultrasound inspection, perhaps? Radiological inspection would definitely show it, but that would be expensive. Mag particle, eddy current and dye penetration test wouldn't help until you had it apart.

But I agree, blown head gasket sounds more likely, and that could be tested for with soap solution with the cylinder under pressure.

 

Welcome to the forum .

The repair of your engine will ultimately depend on the actual problem. Cracked cylinder is very vague. If it is a head gasket then it's replaceable depending on other factors such as deck straightness on the block or head. If there is a crack in a component then depending on the component damaged it could be replaced.

Everything is repairable if caught early enough. If you continue to operate it the way you describe though, the problem will escalate to the point of no return and possibly very expensive. Talk to.your mechanic, you sayed he is trusted. See what the options are.

 

You guys are awesome! Many thanks to the information. Lots to think about. I’ll report my progress.

 

Welcome!