Mechanic says I need new car engine, should I believe them?

Posted by akonba@reddit | askcarguys | View on Reddit | 44 comments

hey everyone! looking for some advice on a no start issue that’s been tough to figure out.

we’ve got a 2011 buick regal that’s been sitting for about 2 years after it suddenly stopped starting. now when we try to start it, the engine cranks strong, sounds like it wants to start, but never actually fires. no sputtering or backfiring, just clean cranking with no ignition.

we took it to the mechanic and paid for 2 hours of diagnostics. they said that: - fuel and ignition systems are working - wiring looks intact - no codes from the scan - scoped the engine and saw some nicks on the piston head

based on that, they told us they suspect internal damage and recommended a full engine replacement. we asked if they were sure and they said not 100%, and they’d need more hours and money to know for sure. i’m just hoping to get some advice on what to do next because it felt like a bit of a jump to go from not knowing exactly what is causing the car to not start to the car needing the engine replaced. but the car’s maybe worth $4k (was bought for $9,000), so we’re ready to scrap it if the engine is truly shot.

would love a second opinion or any ideas on what might actually be going on. thanks in advance!

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SeveralDescription34@reddit

Your second opinion should be from another shop, find one that has a flat rate inspection cost.

TheWhogg@reddit

Nicks on the piston head coupled with other symptoms is...not good. It implies a timing chain has skipped or even let go entirely. It can theoretically be rebuilt but in practice no if valves have hit pistons because of timing.

When it cranks strongly (a bad sign), does it go whomp-whomp-whomp-whomp like a car experiencing a compression cycle? Or whirrrrrrrrrrrr like an engine spinning freely on its starter? Whirrrrrrrr is bad.

What codes?

If the car is dead anyhow, you can't make it any worse. But you don't want to dismantle it and find it's fine, then have to figure out how to properly mantle it again.

No_Awareness_3472@reddit

That car has the 3.8 v6 in it. Virtually indestructible. Get a new mechanic

Bluetex110@reddit

If he already used a scope, he should be able to give an answer.

If a valve broke or made contact with the piston you can clearly see if there is internal damage.

Depending on that i would check compression and if that's fine there is no reason to get a new Engine.

MrAkimoto@reddit

I would suspect clogged fuel system. Try some starting spray into intake manifold. You should probably try another shop too.

icarusislit@reddit

Check your fuel as ok drain the tank and put 2-3 gallons of Petrol in then worry about a mechanic

Murky_Ad_9408@reddit

Go buy a cheap compression tester from harbor freight. Look up the acceptable pressures for your engine. Screw ii in spark plug hole. Test. Very easy and cheap way to find out for sure.

albertpenello@reddit

The simple fact there is no compression test makes me suspect. If the engine rotates smoothly, the first thing you do after checking fuel and spark is running a compression test. This should have been done easily when plugs were out for piston inspection. Crazy to me it wasn't done.

Get a compression and leakdown test. That will give you a pretty close to definitive answer.

gifnotjif@reddit

Try a spare key. Apparently a bad transponder in that gen can disable injectors. There may be a "relearning" procedure, too. Low effort troubleshooting.

6StarBowtie@reddit

From the diag you listed, no, do not trust them.

Spray some starting fluid into it and see if it fires, if it does flush the gas tank and put in a new fuel pump. The pump is likely shot, GM pumps are always kinda meh on some of the older vehicles. The ethanol in the fuel attracts moisture which can corrode the pump internals.

It might have enough umph to get fuel to the rails and maybe even make enough pressure at key on, but when the injectors start pulsing the pressure probably drops out and thats why it wont start.

Ask them what fuel pressure was static after priming and what it was during cranking.

Also a compression and leakdown test should be performed, that will let you know if the engine is blown.

If you parked it running and driving, unless the engine was open and exposed to elements, the mechanical aspects of the motor wont break if they arent running. Or sitting for a decade, 2 years isnt long enough really for rings to size or anything like that and you'd hear it in the cranking as the rings went iver the rough spots in the cylinders. Gaskets and seals can go bad, but it would just make it leak like hell typically, not cause a no start.

verymuchbad@reddit

Fuel gets old. Have you swapped out the gasoline for stuff that will work?

Rare-Beat6134@reddit

sounds like it needs a starter or battery to me.

Puzzleheaded-Duty546@reddit

So the PCM didn't throw any codes that lit up the CEL?

Anti_banana@reddit

The gm 2.4 is notorious for timing chains going bad, so I'd say he is probably right.

ElwoodDiggler@reddit

2nd opinion for sure. If 2 says it needs an engine, look for a beater that runs good with the same engine. Pay someone to swap them out. Scrap donor car

Artistic_Bit_4665@reddit

2 hours of diagnostic time, but no compression test?

The first thing I do is hit it with a little starting fluid. If it starts and runs, it has spark and compression. If it just diesels a little, you know it has compression (a engine will run on starting fluid with no spark).

Pretty much the last thing on a car that just didn't start one day is internal engine failure.

SailingSpark@reddit

So, he scoped it, but never did a compression test? If it's got compression, fuel, and spark, it should run. After that it is timing. Find a new mechanic.

nedal8@reddit

Yep. Needs a fuel test, THEN a compression test, before concluding a new engine.

This is typically a sign that the mechanic needs a new boat motor.

mfkimill@reddit

Also a sign that he doesnt want to work on your car

You have no idea how often this happens. "We don't want to work on your car, so here's an estimate for more than it's worth so you will just junk it".

I do impound towing, and have impounded at least 2 cars that had "bad motors" that I then did the paperwork, got title to, and sold. Running and driving. One had a stalling problem due to the mass air sensor being dirty, the other desperately needed an oil change.

NohPhD@reddit

Or braces for his kid…

Cool-Conversation938@reddit

Yes for sure. Definitely ask for a ride on the boat.

TurboLover427@reddit

Is your engine making forbidden cold coffee in the oil pan? In the coolant area? That is the main question.

ragingduck@reddit

Get a second opinion… FROM A MECHANIC

SyllabubInfamous8284@reddit

I’d expect a compression test. That’s the clearest indicator.

Acceptable_Ad_667@reddit

Find a real mechanic. A good mechanic would have had it diagnosed in under an hour. Compression test and fuel is the first thing you do

ImpliedSlashS@reddit

Did they do a compression test? Compression plus fuel plus spark equals start. One of the three has to be missing.

Old_Confidence3290@reddit

I think for 2 hours, they owe you a compression test.

supern8ural@reddit

Did he do a compression test?

NoRegret1893@reddit

Was this a mechanic or your Door Dash driver?

TactualTransAm@reddit

You say it cranks strong? Like. Cranks really really fast? Like it's not fighting compression? Did they do a compression test? I'm thinking that's why they scoped the cylinder, or at least that's why I would scope a cylinder in this situation. They could be correct or couldn't be.

ALG2003YT@reddit

Spray a small blast of starting fluid in the air filter. If it fires up and then shuts off, it could be a fully flat or low voltage battery. Charge or boost the batteryehen ceanking. If that doesn't work, you might have to drain the fuel tank and refill it. Gas gets really nasty when it sits. Run some fuel injector cleaner through it when you do

South_Bit1764@reddit

As everyone else says, try someone else. Mobile mechanics can be hit and miss, but it might make more sense than towing it from shop to shop.

It’s hard to really say from my couch, it sounds more like a crank/cam sensor.

If it was running fine then suddenly not running, it probably didn’t just completely loose compression and it probably didn’t snap a rod. So it will mostly likely be electronic.

Cam and crank sensor codes might not show up if it hasn’t ran since the computer was reset. They are also difficult to diagnose with a multi meter. Unfortunately, swapping a new one in is the surest way to know.

Fortunately since you can probably wait a day, you can get one on Amazon cheap, that’s probably what I’d do because they are cheaper and there is no one to ask questions when you return it.

Hersbird@reddit

Fuel, spark, compression. So if it has fuel and spark they should test compression. If compression is off, then look at what may be causing that cylinder to be off. Scoping is a tool, but is compression on that cylinder good? If not then there is something wrong. It could just be a head problem but if they see some damage to the pistons they are saying longblock, not just heads.

I'd look at putting a used junkyard engine in it.