Hi all, I have a 2010 RX 350 with 140K miles on it. Been taking it to the dealer till 2022 for regular maintenance. Since then have used a local place for oil changes .

3 months ago , the check engine , check AWD lights came on . Code reader said cylinder misfire and the local shop near me replaced the spark plugs saying they were worn out. The brakes and shocks were due for replacement too so I had that done then.

It worked fine since then , but yesterday I had the same lights come on - code reader said cylinder misfire again . I took it back to the same shop who now say that I need a new motor and gasket and estimated cost is 6-7K ! They say they found a wet cylinder due to excessive coolant leak.
I haven't noticed any low coolant recently or obvious leaks.

Does this make sense? What could I have done to prevent this and is this worth repairing?

Trying to figure out what to do here ..I was expecting this car to last a few more years . I am planning on getting a second opinion - maybe from the dealer.

 

You need to read the OBDII codes and report them here.

 

You need a second opinion from another independent shop. I doubt they pulled the plugs again and found a wet spark plug, which is how they would diagnose a wet cylinder.

It may just be one of the rear coils failed, or something else and they see you as a source of income, so decided to say you need a new engine..

If you actually need an engine, a used one will be far cheaper. Do not let any shop rebuild yours and do not buy a new one. It is economics. Check the used car trade in value of your RX before this problem.
Or clear the codes and trade it in to CarMax.

 

Thanks all. There are 4 codes total - but a repeat of the 2 below
P0300 ( same code twice )
P0302 ( same code twice )

I am planning to take it to another shop that was recommended - but it is about 20 miles away. Can I drive it there or do I need to get it towed ?

 

yes agreed, I don't think it's worth a rebuild ..was just hoping for a better diagnosis, lol.

 

Wet cylinder can be due to multiple reasons and a proper diagnosis is needed.

If it is due to head gasket leak [coolant in cylinder] a simple pressure test of the coolant system can be done. The coolant pressurizing kit can be loaned from auto stores. Just make sure the fittings can adapt to your system and do not go beyond spec .. specially the safety release .. which is MAX and typically the system is 20% below that. The drop in pressure only will tell if there is a coolant leak, which can be anywhere.

The next is to put borescope down the spark plug hole and with the coolant pressurized one should be able to see the coolant entering the chamber.

Compression test is another test.

You need your mechanic to do due diligence and not shoot out opinions.

If there were circumstances leading to the failure like engine overheating etc then yes the opinions may be biased but worst casing to scare a customer is not a valid option.

Driving with repeat misfire is not a good idea. You can let the eking idle and see if the misfires go away.

Salim
ps: A leaking fuel injector may also cause the plug to be wet.

Salim

 

Check the exhaust, white smoke? Check the antifreeze, does it smell burnt, is it bubbling in the tank? Photo of the spark plug, is there a gray white coating or .. clean from steam? If the gasket is broken, then it should go somewhere . Look at the oil filler plug, oil in the engine, swelling of the cooling hoses. The heating does not heat well. You can see all this yourself or with a friend. If antifreeze gets into the combustion chamber, look for it on the spark plug on the exhaust and of course in the antifreeze itself a pressure test in the system is the best solution

 

https://www.tomorrowstechnician.com/...sit-diagnosis/

 

Yes there is white smoke coming, I just checked this myself. No burnt smell in antifreeze - level is about more than half full.

I'll try to look at the other things later today.


I did call them and ask for more details - apparently they did do a borescope - these are the notes -

"upon finding misfire on one cylinder we went to swap plug and coil from cylinders 2 and 4, all connections found broken, removed plugs and noticed cylinder 2 was wet, I then bore scoped cylinder and found excessive coolant in cylinder diag stopped vehicle needs a motor"

So it does sound like coolant leak/blown gasket? In that case - is the only option a new motor or can just the gasket be replaced - is that even worth it?

 

A fresh engine with low mileage would be nice. It's a question of money and trust. How was the engine stored, what is its condition. Warranty. Compare prices, repair, replacement, of course, take into account the associated costs. These motors are on many models. But this does not mean that you take it out, put in another one and go. There are differences. 2gr fe early and later. I would look for 2010 so that the connection does not cause questions.

 

These cylinders are at the front of the engine and easy to access and check.

Why were all the connections broken on the coils when they were the guys who just replaced your spark plugs? If they broke them doing the spark plug install, they should not have let if out of the shop before repairing the coil pigtails connections. It is obvious they broke your coil wires! I wonder if they knew they were damaged, and that the damaged wires would fail soon and that you would return so they could then up the game and sell you and engine that you may not need.

This makes me very suspicious of their diagnosis.

You certainly need another opinion. You can use this database to hunt for other recommended shops by city and state. If you find any near you, cross check on Google or Yelp as some ratings are very old.
https://www.cartalk.com/mechanics-files

If needed, Ask about the cost for just replacing the head gasket. They can check the heads for warping at that time?

​​​​​​If they are not lying to you, this can get expensive and you may want to consider how much you can or want to invest in this vehicle.

 

Good advice from Clutches.

So there is a leak in cylinder 2 [you can do a second confirmation test by cold pressure testing of the radiator].

Then there will be the decision point to repair or replace (engine) or replace vehicle.

Before mental walk through the repair, there are essential history questions [you still need to think about general condition of the vehicle and do a honest $$$ analysis to repair or punt]. Did the engine overheat? If yes then there is most likely deformation issues. If not proceed:
The chances are that the head gasket has developed a leak. Fortunately the issue is in the front bank, which is easier to work in place. Some one has to undo timing component and remove the head AND Measure if the head and the block are flat within spec. Then replace the head gasket and build it back.

Net is there will be some work that needs to be done to determine if the current engine is salvageable. Ask the mechanic/machinist the labor involved till the measurements and to put it back.

Salim

 

An oil analysis can verify if coolant is getting into the oil. Not expensive.

 

 

Just wanted to post a quick update -
I did a pressure test myself and can confirm the leak. Also white smoke out of exhaust. I tried looking at the oil and it seems more chocolate colored than normal but not 100% sure.

I took it to one more shop about 10 miles away who did another borescope and confirmed the coolant leak but gave me a really high labor cost for just diagnosing further - eg if it's just head gasket or needs an engine( $3000 ) . I called the dealer who wants 5500 for diagnosis !

I do not think it is worth it at this time. I can't keep driving it around to shops either and would need to tow it - it overheated a couple of times while driving back from the above mentioned shop - I pulled over and stopped for a bit then made it home.

I plan to call one more shop next week but right now my thought is to just replace the car. The car also has some minor body damage because I dropped collision on it a year ago and as luck would have it - someone hit my car and drove off .

The main issue is trust and finding a good mechanic .
At this point I am just going off some recommendations for independent shops who apparently are not that interested as soon as they hear the age of the car. I even called a shop that apparently specializes in Japanese cars and he just said he doesn't even look at coolant leak issues but sends it to the dealer

I heard there are products for leaks ( K-seal ) etc but I also see bad reviews about them . At the most this may be short term solution ?



Thank you all so much for your help - it was invaluable.
If anyone has any ideas on what I could have done to prevent this , that would be much appreciated too. I did the normal recommended maintenance/oil changes so far .