Before you go buying a new engine I recommend putting a tablespoon of engine oil in the low compression cylinder and checking your compression numbers. If it goes up dramatically then you have a piston ring not sealing issue or a piston that is cracked between the ring lands. If that's the case I would resurface the heads and replace pistons/rings.
Missfire Cyl#2
- Thread starter Crackership
- Start date
Before you go buying a new engine I recommend putting a tablespoon of engine oil in the low compression cylinder and checking your compression numbers. If it goes up dramatically then you have a piston ring not sealing issue or a piston that is cracked between the ring lands. If that's the case I would resurface the heads and replace pistons/rings.
gamefreakgc
Elite Member
WAIT!!! Don't ditch the engine yet. There's a good chance your exhaust valve looks like this:
I've encountered several 5VZ-FE's with burnt exhaust valves. While it's not super common, it does happen. You will want to do a leakdown test (if you have a buddy with an air compressor you can buy the tool yourself) and see if it's the valves. If yes, it's totally repairable. I recently purchased a 4Runner that had a very badly burnt exhaust valve, it had 3 cracks in it!
plcfcng
Member
Did you do a wet compression test ? If the number stays close to the same then it will be valve problem thats a good thing if the number goes way up then it's a ring problem that's not good. After that then pull the head they guy before me is right a burn't valve is not a huge deal. When you pull the head send us a pic.:bowl:
Crackership
New member
WAIT!!! Don't ditch the engine yet. There's a good chance your exhaust valve looks like this:
I've encountered several 5VZ-FE's with burnt exhaust valves. While it's not super common, it does happen. You will want to do a leakdown test (if you have a buddy with an air compressor you can buy the tool yourself) and see if it's the valves. If yes, it's totally repairable. I recently purchased a 4Runner that had a very badly burnt exhaust valve, it had 3 cracks in it!
I have an air compressor, just need to get the tool for a leakdown test.
Would it change your opinion at all if I said the engine has 260k miles on it?
I'll admit, most of my experience dealing with head repairs/machine work has been on Porsche or Alfa Romeo engines, but all the machine shops I've worked with start at about $600/head to clean them up, replace valve stem seals, set valve clearances and re-surface. For a pair of heads, that's $1200 and any replacement parts (like valves) would be extra. Add in a set of head gaskets and we're at the cost of a JDM engine, and I've still got 260k on the bottom end. This is where my thought train is going, anyway. I understand that the JDM engines aren't a direct drop in, but most of the things I'd need to handle to facilitate the swap are good maintenance items anyway.
by wet compression test, you mean by dropping some oil in the cylinder first, right? I'll do that this evening
Last edited:
plcfcng
Member
yes if you have a squirt can I just give it a 2 squirts and do the test. It is also a good idea when you pull spark plugs keep them in order so you can look at them. It's called taking a plug reading it can tell you a lot. If you have already mixed them up it would take driving it a 40 or so miles to give you an idea what's going on in the cylinder. At this point don't worry so much about a plug reading. As far as cost go I work with a machine shop they cut the valves, rest lash, and resurface for about 500$ take your valve seals from the head gasket set. if you have a cracked head if you get refurbished make sure to check valve lash. I got a set that was way out I have a set of heads but it a long drive to get them there.
lane:
lane:
Last edited:
gamefreakgc
Elite Member
It depends. I blew my engine at 220K miles but I had metal shards in the oil so it was time to replace it. Had two cylinders with low compression at that point too. A valve job shouldn't be in the $600 range at all. I just had a set of heads resurfaced and hot tanked for $160 and you'd only have to have one done with 1 valve replaced. This isn't an over engineered German cylinder head, it's a very simple Toyota one.
If you do want to go for a JDM swap, there's a lot of parts you'll need to move over from your USDM. I had a heck of a time getting the JDM crank pulley off and added about 20 hours to the job of moving all those parts over, it was a ton of extra work. BUT my new engine is fantastic, wet compression is 220 PSI per cylinder!
Crackership
New member
So, I'm a little torn. But, the facts are, I bought this rig knowing it had a misfire and that there was a good chance it needed as much as an engine. The price I got it for very appropriately represented the possible work required. I know nothing about the history of the engine, just what the odometer tells me and the fact that I have very low compression on one hole. I'd like to be able to drive this thing for 10 years and do some light wheeling as often as possible and if like to be able to comfortably trust it won't leave me stranded. On the one hand, solving the immediate issue is definitely the cheapest option but the nuclear option of a JDM engine puts me in a known-good place as far as long-term engine health. I'm leaning the direction of "just swap the engine and call it handled", but I do really appreciate the dissenting opinions. It's worth making sure all options are considered
Last edited:
gamefreakgc
Elite Member
Yeah that makes sense. A full swap will give you a better engine that you can depend on, rather than waiting to see if the old one blows up again.
Crackership
New member
Just to close this thread, I bought a JDM engine, and dropped it in. Nuclear solution, but very effective. Thanks all for all your help!!
