Toyota Nation Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
Hello everyone - I'm new to this forum so please excuse me if I'm asking a dumb question :)

I bought my 2004 Tacoma new and its been the most reliable vehicle I've ever owned. Today it has just better than 295,000 miles - and is still my daily commuter. The check engine light came on a few months back so I took it to a mechanic - not too much experience with this shop but I think I can trust them. He tells me the light is telling me there is a misfile in cylinder 2 (or maybe 3, I don't remember). After checking he found pretty low compression in 2 cylinders and says I need a valve job - he could not adjust the valves enough to get the compression back. Also, he says, if I do a valve job on an engine with high mileage, like mine, I likely will see the engine started burning oil (never has before) and should probably bite the bullet and do a complete rebuild (pretty spendy).

I'm not ready to send such a trusty vehicle to the crusher so I'm thinking I'll do the rebuild. Does this advance sound about in-line from what you'd expect from an engine with just under 300K miles?
 

·
Moderator
2015 4 Runner SR5
Joined
·
3,713 Posts
Hello everyone - I'm new to this forum so please excuse me if I'm asking a dumb question :)

I bought my 2004 Tacoma new and its been the most reliable vehicle I've ever owned. Today it has just better than 295,000 miles - and is still my daily commuter. The check engine light came on a few months back so I took it to a mechanic - not too much experience with this shop but I think I can trust them. He tells me the light is telling me there is a misfile in cylinder 2 (or maybe 3, I don't remember). After checking he found pretty low compression in 2 cylinders and says I need a valve job - he could not adjust the valves enough to get the compression back. Also, he says, if I do a valve job on an engine with high mileage, like mine, I likely will see the engine started burning oil (never has before) and should probably bite the bullet and do a complete rebuild (pretty spendy).

I'm not ready to send such a trusty vehicle to the crusher so I'm thinking I'll do the rebuild. Does this advance sound about in-line from what you'd expect from an engine with just under 300K miles?

Welcome to the site Jeffrey!


Get a second opinion. Low compression may not be due to a valve, and I am not aware a valve job (which if he means replace valves and not just the seals) would cause oil to burn. Sounds to me like he is trying to dupe you into a rebuild.


A misfire can be due to a faulty coil, bad gas, a host of things. Check reviews in your area for shops people are giving good reviews for and get an opinion form them as well.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
thanks for your reply! I should have mentioned he told me that after a valve job the newly increased compression in the cylinders 'may' cause the engine to burn oil because it could start pulling the oil through the worn rings. because of this, I should consider a full rebuild - apparently, I can't just do the valve job first and if I do see oil starting to burn, rebuild the rest of the engine later?
 

·
Registered
08 Toyota Camry 2AZ-FE R9K Tuned
Joined
·
5,547 Posts
Given that you are getting close to 300,000 miles, I would consider it to be a good time for a rebuild. Probably just not with that mechanic. Your choice in the end.
 

·
Moderator
2015 4 Runner SR5
Joined
·
3,713 Posts
Is this a 4 or 6 cylinder engine?


You need to address the misfire - not so much the compression issue if the compression is not way out of whack. He should have ran compression on all cylinders and recorded their readings. Can you post those?


It is possible to replace the valve seals (which would be the issue with the compression IF that is causing it) with the engine in the vehicle. At that mileage it is not crazy to think the valve seals could use replacing. And like Vang states above a rebuild around 300k is not out of place. Folks are running their engines at over 400k with the original goodies - just depends.


A 4 cylinder engine is pretty easy to pull and replace. The majority of the cost you would encounter for something like this would be to pull and replace the engine. Once out, the rebuild is hundreds of dollars worth of parts, if there is no issue with the integrity of the block and all that. But I would not worry about it right now if it is running OK. Get the source of the misfire identified.


You can swap coils and see if the misfire moves to the location of the swapped coil. If so the coil is the problem. But it may be the seal.


Let's say you do need to replace the valve seals. If it were me, and the vehicle works and you want to keep it, I would rebuild. The shop may want to take out the engine, and if so then there is not a good reason NOT to rebuild at that point: new piston rings (probably new pistons), racers and all that, new engine seals, new head gasket, oil pump checked and repaired/replaced, all kinds of things. Money is the thing that makes it hard. If you can pull the engine and place it yourself you will save thousands of dollars.


If the seals are bad, shop around for a place that will put new seals in with the engine in the truck - that is your least cost alternative. If all will only do it if they pull it, then seriously consider a rebuild. Shop around for a rebuilt. I bought a rebuilt engine for my Camry for $1,800 delivered. Been working perfectly.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #8
second opinion

Got a second opinion back - pretty much backs up the first with the same recommendation. At a minimum, the engine needs a valve job - full rebuild would not be a bad idea. Here's some info I got about the compression test.

#1 cylinder 110 PSI,
#2 cylinder at 50 PSI - 100% leak down,
#3 cylinder 80 PSI - 30% leak down,
#4 cylinder 110 PSI.



at this point, I'm leaning toward the rebuild - still waiting on the cost estimates. At just under 300,000 miles, the only repair I've had to do is replace a bad alternator (~5000 miles ago), I guess I should be pretty pleased. a rebuild should get me to 500,000 :smile:
 

·
Moderator
2015 4 Runner SR5
Joined
·
3,713 Posts
May have a head gasket issue as well. For giggles, contact KarKing Auto in Ontario, CA. Ask them what they have for a rebuild of your engine:


https://karking.com/


it will come ready to install, so you just pull and replace. You more than likely can pay a guy from a shop to come over and do that. Or have the engine delivered to the shop and have them pull and place it.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #10
thanks to everyone for their advice. I ended up getting a valve job done - just got it back the other day. now my 300,000-mile old engine is running like new again. the difference is impressive. the mechanic sounded very impressed about how clean the engine is and the overall condition inside. I think it's pretty reasonable to hope for another 100,000 miles now!
 

·
Moderator
2015 4 Runner SR5
Joined
·
3,713 Posts
thanks to everyone for their advice. I ended up getting a valve job done - just got it back the other day. now my 300,000-mile old engine is running like new again. the difference is impressive. the mechanic sounded very impressed about how clean the engine is and the overall condition inside. I think it's pretty reasonable to hope for another 100,000 miles now!
:thumbsup:
 

·
Registered
Joined
·
1,539 Posts
thanks for your reply! I should have mentioned he told me that after a valve job the newly increased compression in the cylinders 'may' cause the engine to burn oil because it could start pulling the oil through the worn rings. because of this, I should consider a full rebuild - apparently, I can't just do the valve job first and if I do see oil starting to burn, rebuild the rest of the engine later?
Yes, you could do this but, you save lots of money on labor if you do it all at the same time. A true engine overhau/full rebuildl involve complete dissassembly of the engine. Lots of work and money.
I believe Toyota recommends replacing rather than reboring the engine block if there is noticable wear/taper in the cylinder bores. It may be possible to do a light hone, re-ring, and replace rod bearings with out removing the engine but, to do that the heads have to be off, thus the savings in labor.
 

·
Registered
Joined
·
1,539 Posts
Yes, you could do this but, you save lots of money on labor if you do it all at the same time. A true engine overhau/full rebuildl involve complete dissassembly of the engine. Lots of work and money.
I believe Toyota recommends replacing rather than reboring the engine block if there is noticable wear/taper in the cylinder bores. It may be possible to do a light hone, re-ring, and replace rod bearings with out removing the engine but, to do that the heads have to be off, thus the savings in labor.
OK, just saw your repair was successful. Congrats!
 
1 - 13 of 13 Posts
Top