Low compression results

Hey folks,
My truck threw a p0300, p0301 and p0303 code recently. I changed the spark plugs and coil packs which didn't change anything. I had a compression test done. I'm getting 70 - 175 - 75 - 175. Cylinders 1 and 3 go up to 95 with a little oil then retest. No leak down test.

I've owned the truck 3 years. It has 175k miles, I've driven it 50k since I bought it. It's only given me problems 2 periods of time, where it would occasionally not start or die in idle after starting the truck. Both times it did this, first time a few months after I bought the truck, then again this winter in Washington, it was problematic intermittently for a week or so, then was fine again. The first time the MAF got cleaned, but that didn't immediately fix it, it just stopped being problematic after a bit. It has always had a bit of a rough idle, and never gets better than 18mpg, generally always around 16, even though it's a 4 cyl 2.7l.

It's never overheated since I've owned it, not blowing smoke out of the tailpipe, I've kept up with routine maintenance. The mechanic says maybe a valve job, maybe an engine swap.

Anyone want to weigh in on what you think my options are? Should I ask for a leakdown test? I'm wondering what an avg price for a valve job is, and for an upper engine rebuild, and for a full engine rebuild in Southern California. I'm trying to make sure I'm informed going into the mechanic, and that I'm not getting hosed on price. Thanks all.

 

what year ....... How Many Miles ??????


leak down wont look any better than a compression test

good thing about a leak down test at 100psi

U Will Hear Where the air is escaping....... !!

passed the valves

bad rings

or head gasket

U will hear if U are quiet /payin attention

so far it dont look good.............if U are seriously considering a rebuild ( NO such thing as a Partial ! )

weight that against a replacement engine......... depends on how long U plan to keep Ur truck

 

175k, 2002

 

Uv been having issues for a while

maybe since Uv bought the truck used

no tellin what was done or neglected

think about how much U want to spend if U intend to keep the truck in the future

no time for a band aid fix

just means U will have to spend $$$$ twice

 

Without determining where you’re losing pressure you’re not going to know what the problem potentially is. Leak down test, then verifying proof of concept will let you know how to fix and how much the range of prices it’ll take to fix it at local places.

 

Compression issues sounds like hg/warped or cracked head. Possibly both. I ran my truck 30k miles without noticing mine, until i would high rpms and it gradually got worse. Ended up getting to where above 4k rpms id consistently missfire, and had rough starts when the truck was up to temp. I never overheated mine, must've been PO. Never saw smoke, but was losing coolant from exhaust. Very minimal white smoke on startup that was it. Cyl 2 was 160 psi, and 3 was 118 on compression. Changed both my hg and head to get it done with

Leak down then go from there

 

a leak down test at this point is a waste of time and money as the air used for testing will go the path of least resisitance, past the bad valves. You can go with an aftermarket head or a factory head or get yours rebuilt. An aftermarket drop on ready to go head is apx $750 figure about $1500 ish total for the job.

 

Good point - the reason why I suggested it was the shop is giving him *her wildly varying reasons for low compression which I suggested getting verified since if they’re going to not even run a full diagnostic on an easy to diagnose issue, I’d surprised if they didn’t give him some up charges for bs reasons they are doing work on various things. My recommendation would be bring it to another shop that knows how to figure out the issue accurately then. If they can’t figure out the issue I’d be hesitant to let them fix the truck with such an expensive fix. Been reading a bunch of stories on here where shops go through a bunch of messed up diagnostic procedures which end up costing the customer tons of money. Points to incompetence or outright dishonesty or both.

 

Have the valves ever been adjusted? If not, definitely check the valve clearances. Might have a couple burnt valves.

 

This is my concern, and I've been doing a bunch of research to try to understand the problem so I'm not getting hosed. I've been quoted $2500 to $4500 for different procedures. It's a whole lot of money.

 

What's PO?

Interesting, mine was having that starting issue after warm as well. It will occasionally blow a smell that is chemical/eucalyptus through cab. Not all the time, though. It's only just gotten to rough starts. It recently was having enough trouble going up hill that I had to run it at 4rpm in 2nd gear cause there wasn't enough power in 3rd to get up. F*ck.

 

How do you find a shop that knows how to figure out these issues? Dealership? I'm in Pasadena, CA but haven't been here long enough to have an established mechanic. Already left one shop who was a jerk and insisted I replace the coil packs just to see if that's the problem, a $450 unnecessary fix, for another that's quoting me wildly expensive numbers for different potential fixes. Add to the mix that I'm a woman.

 

@eon_blue is in your area. He might know one. @GHOST SHIP also

 

Op, in addition to the advice above, I would find a NAPA or an O Reilly's and ask for the manager of the store and seek their recommendations. They KNOW who operates a decent shop by the amount of parts returned, not the amount ordered. If a repair shop returns lots of parts their techs are just parts re-placers and not diagnosticians. If you hear the same shop name over and over, it it usually a good sign.

 

RPM Garage is a great shop in Monrovia that almost exclusively works on Toyotas and Toyota 4x4s... That being said they mostly do installs and alignments and are always busy with work. But they did a timing belt job for me recently, I just don't know how much of a 'diagnostic' type of shop they are. But could be worth hitting them up to see what they say.

They're a great bunch of guys, friendly and the owners are really cool.

 

if U are having issues i dont understand running the engine to possible ruin

 

This was my first thought when I read your post. The 2.7 liter engine is prone to burning up exhaust valves. The valve lash tightens over time causing the exhaust valve not to close all the way. When the air/fuel mixture is ignited by the spark plug, some of the hot gasses of the combustion process blow by the valve and either burn up the valve, burn up the valve seat, or both.

I would do a leak down test and figure out where the compression is going. I'm suspecting when you pressurize the bad cylinders and put your ear up to the exhaust pipe, you're going to hear escaping air. If I'm right, you're going to have to pull the head and do a valve job or just buy another remanufactured head and install it with a new head gasket.

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