Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 12th November 2009, 22:39   #1
BHPian
 
Join Date: Nov 2009
Location: Bangalore
Posts: 26
Thanked: 0 Times
Default Open heart surgery on Optra?

Hi,
Hope I'm posting this in the right place.

I've been in the habit of buying what I think are well engineered cars used, and keeping them in good shape. One of them is my Chevy Optra 1.6, that I bought 9 months ago with 44000 kms on it. It's been running like a dream, and I've clocked 12k kms more on it, with some really cool Blr-Ooty runs.

Recently, after my last Ooty run, the ac wasn't cooling well, so I took it in to Kropex (Chevy dealer on Hosur Rd) and was told the compressor needed to be replaced - estimate Rs49k. After picking up phone and jaw from floor, told them I'd get the compressor myself, if they'd just fit it; after some hemming and hawing, they agreed. Since I got it back two weeks ago, ac was fine, but the machine felt like it had aged and got alzheimers; there was just no accelleration, and it was jerking slightly like it had the ague at lower gears, and would groan up the slightest gradient. After patient repetition, I finally had the morons at the shop actually pay attention, only to be then told first that my clutch needed replacing, and then that (clutch my heart) it needed engine overhaul.

They told me compression was down (plausible) and that was because the piston rings were down - they'd be able to tell exactly how many, only after opening up the engine. I said what about checking compression on each cylinder with a guage? they said they don't have the adapter (my incredulous gape went unnoticed).

I'm now in the unenviable position of deciding whether the car needs open heart surgery. I'm going to get second and third opinions - Sanjay of Race Dynamics, and probably Ranjit Auto Care (I live in Koramangala, so proximity is a help).

I need some advice on next steps. The mechanic at Kropex validated his diagnosis of piston rings by showing that the dipstick well sprays oil when engine is warm and revving, which apparently shows "compression backing". While Sanjay has told me he will check compression tomorrow with a guage, the guys at Ranjit Auto Care said they'd put it on the examiner and check.

Can anyone tell me if there is some reliable shop for engine work on optra 1.6, or alternatively, what i should be looking for when these guys are rooting around under the hood? What are the questions i should be asking?

Any help is appreciated, as I'd rather keep the car in good shape than trade it in for peanuts. Should I persevere, or cut my losses?

Last edited by Jaggu : 13th November 2009 at 12:34. Reason: Readability, paragraphs helps. Thanks
float is offline   Reply With Quote
Old 12th November 2009, 23:01   #2
Distinguished - BHPian
 
SS-Traveller's Avatar
 
Join Date: Jan 2009
Location: New Delhi
Posts: 6,656
Thanked: 11,061 Times
Default

Quote:
Originally Posted by float View Post
I'd get the compressor myself, if they'd just fit it; after some hemming and hawing, they agreed.
Since I got it back two weeks ago, ac was fine, but the machine felt like it had aged...

The mechanic at Kropex validated his diagnosis of piston rings by showing that the dipstick well sprays oil when engine is warm and revving, which apparently shows "compression backing".
"Back-compression" shows up as smoke from the dipstick hole and the oil filler cap - oil splashing from here when the engine is warm and running is a good sign that your oil pump is in good health.

I'd suggest you check the compression on each cylinder with a compression guage anyway (a wise mechanic can even tell with his thumb on the spark plug hole - cold engine, of course!), but I suspect the fault lies with your fuel injection system. Open heart surgery does not sound warranted right now.
SS-Traveller is offline   Reply With Quote
Old 13th November 2009, 06:10   #3
BHPian
 
Join Date: Mar 2009
Location: Bangalore
Posts: 265
Thanked: 201 Times
Default

RAC in Koramangala is the best place only if Ranjeet is seeing the trouble personally. Forget it if any of his mechanics sees it. This is my personal and frequent experience

I would also recommend Ali garage ( behind Sony World ). I have no personal experience, but heard of his expertise from many colleagues.
Ravindra M is offline   Reply With Quote
Old 13th November 2009, 06:45   #4
BHPian
 
Join Date: Nov 2009
Location: Bangalore
Posts: 26
Thanked: 0 Times
Default

@ss-traveller
thanks, that helps - will post update after sanjay looks at it today
float is offline   Reply With Quote
Old 13th November 2009, 07:38   #5
Senior - BHPian
 
MileCruncher's Avatar
 
Join Date: Jan 2009
Location: Mumbai
Posts: 3,993
Thanked: 356 Times
Default

@ Float: I would say this is too early in the engine life to warrant a ring change. So please get the compression checked. Loss of power can be attributed to clogged injectors, bad spark plugs or even bad fuel.

But if god forbid, compression is low in any of the cylinders, you should change all the four piston rings. Also while at it you should also check the clearnce between the ring and cylinder wall.
MileCruncher is offline   Reply With Quote
Old 13th November 2009, 08:18   #6
Senior - BHPian
 
Ravveendrra's Avatar
 
Join Date: Jan 2008
Location: Hyderabad
Posts: 1,391
Thanked: 405 Times
Default

Quote:
Originally Posted by MileCruncher View Post
@ Float: I would say this is too early in the engine life to warrant a ring change. So please get the compression checked. Loss of power can be attributed to clogged injectors, bad spark plugs or even bad fuel.

But if god forbid, compression is low in any of the cylinders, you should change all the four piston rings. Also while at it you should also check the clearnce between the ring and cylinder wall.
Improbable but quite possible. Remember that the car was run for 44K km by someone else. Any high revving of a cold engine or running without oil can kill the engine necessitating a ring change. Hopefully the problem will disappear with a fuel system de-clogging and change of plugs. If a ring change is indicated, all rings have to be changed.

Cheers,
Ravveendrra is offline   Reply With Quote
Old 13th November 2009, 08:25   #7
BHPian
 
Join Date: Nov 2009
Location: Bangalore
Posts: 26
Thanked: 0 Times
Default

@ss-traveller & milecruncher
fuel injection issue hadn't crossed my mind, but now that you both mention it, i remember when my cielo had similar issue, it turned out to be something simple like cleaning a sticky piston in the fuel injector.
thanks guys, i already feel enlightened and empowered to kick grease monkey butt if i'm fed a line of horse manure.

@fiery enzyme
flattered bro; not having anything worthwhile to contribute is a familiar feeling for me too - memory of my recent inane interjections at product meeting is cringeworthy
float is offline   Reply With Quote
Old 13th November 2009, 09:09   #8
BHPian
 
Join Date: Nov 2009
Location: Bangalore
Posts: 26
Thanked: 0 Times
Default

@ravindra m
i tend to have the same opinion of rac; which is why i'm going to sanjay of race dynamics - he used to work at rac, and i'm hoping he has decent diagnostic skills.
ali garage, i've had a couple of indifferent to bad experiences, so i'm not too keen on them
float is offline   Reply With Quote
Old 13th November 2009, 12:38   #9
Team-BHP Support
 
Jaggu's Avatar
 
Join Date: May 2004
Location: Bangalore
Posts: 17,848
Thanked: 7,691 Times
Default

Do a compression check, ensure they disconnect the fuel pump so that fuel is not sprayed and wash off the oil, resulting in low reading.

Take it from there.
Jaggu is offline   Reply With Quote
Old 13th November 2009, 12:43   #10
BHPian
 
Join Date: Nov 2009
Location: Bangalore
Posts: 26
Thanked: 0 Times
Default

just had the compression checked at race dynamics, all 4 cylinders showing 170psi; called kropex to check what is recommended. after repeated follow up, they said 9.5. told them i'd already checked tech specs, and that was compression ratio of 9.5:1.

Anyways, so karthik and sanjay at rd said that was fine, and in any case logic dictates that if piston rings were down, it's well nigh impossible that all 4 would give exact same reading; so loss of compression ruled out. then they fixed some guages and ran the car; they're now saying it's probably a clogged catalytic converter. they're going to clean the cat, and we'll check performance again at around 5pm. hope that solves it.
float is offline   Reply With Quote
Old 13th November 2009, 13:47   #11
BHPian
 
Join Date: Aug 2005
Location: Mumbai
Posts: 275
Thanked: 62 Times
Default

Quote:
Originally Posted by SS-Traveller View Post
"Back-compression" shows up as smoke from the dipstick hole and the oil filler cap - oil splashing from here when the engine is warm and running is a good sign that your oil pump is in good health.

I'd suggest you check the compression on each cylinder with a compression guage anyway (a wise mechanic can even tell with his thumb on the spark plug hole - cold engine, of course!), but I suspect the fault lies with your fuel injection system. Open heart surgery does not sound warranted right now.

Quote:
Originally Posted by MileCruncher View Post
@ Float: I would say this is too early in the engine life to warrant a ring change. So please get the compression checked. Loss of power can be attributed to clogged injectors, bad spark plugs or even bad fuel.

But if god forbid, compression is low in any of the cylinders, you should change all the four piston rings. Also while at it you should also check the clearnce between the ring and cylinder wall.
+1 to that, looks more like an injector problem
an_and is offline   Reply With Quote
Old 13th November 2009, 14:00   #12
Senior - BHPian
 
Ravveendrra's Avatar
 
Join Date: Jan 2008
Location: Hyderabad
Posts: 1,391
Thanked: 405 Times
Default

Quote:
Originally Posted by float View Post
just had the compression checked at race dynamics, all 4 cylinders showing 170psi; called kropex to check what is recommended. after repeated follow up, they said 9.5. told them i'd already checked tech specs, and that was compression ratio of 9.5:1.

Anyways, so karthik and sanjay at rd said that was fine, and in any case logic dictates that if piston rings were down, it's well nigh impossible that all 4 would give exact same reading; so loss of compression ruled out. then they fixed some guages and ran the car; they're now saying it's probably a clogged catalytic converter. they're going to clean the cat, and we'll check performance again at around 5pm. hope that solves it.
That is good news. Besides checking the exhaust, please also have the fuel filters, air filter, fuel lines, pump and injectors cleaned. This should help.

Cheers,
Ravveendrra is offline   Reply With Quote
Old 13th November 2009, 14:07   #13
BHPian
 
Ford Rocam's Avatar
 
Join Date: Feb 2005
Location: Mumbai-India
Posts: 880
Thanked: 16 Times
Default

Quote:
Originally Posted by float View Post
just had the compression checked at race dynamics, all 4 cylinders showing 170psi; called kropex to check what is recommended. after repeated follow up, they said 9.5. told them i'd already checked tech specs, and that was compression ratio of 9.5:1.

Anyways, so karthik and sanjay at rd said that was fine, and in any case logic dictates that if piston rings were down, it's well nigh impossible that all 4 would give exact same reading; so loss of compression ruled out. then they fixed some guages and ran the car; they're now saying it's probably a clogged catalytic converter. they're going to clean the cat, and we'll check performance again at around 5pm. hope that solves it.
Yep Piston Rings & Gasket is ruled out, what is needed now is a Leak down Test.
Ford Rocam is offline   Reply With Quote
Old 13th November 2009, 14:23   #14
Senior - BHPian
 
esteem_lover's Avatar
 
Join Date: Jul 2006
Location: Madras/Py
Posts: 7,554
Thanked: 447 Times
Default

Seems like the dealer did not like you buying the compressor outside, now they will start blaming the comp for the loss in power.
esteem_lover is offline   Reply With Quote
Old 13th November 2009, 16:01   #15
BHPian
 
Join Date: May 2004
Location: Hyderabad
Posts: 223
Thanked: 20 Times
Default

now-a-days most of the time, the dealers are very lenient on the customers. The dealers take the customers very light. Whom to blame.... it boils down to our india legal system. Every dealer is taking the customer for a ride. Unless the customer is very influential, they do not bend to a normal people.

A different but a similar experience with one of my friend. The tata guys hesitate to replace the spoiled condenser. Initially, the car was for a/c repair and dealer repaired and delivered the car back. but again the same problem - A/C not working. When insisted on his rapair work, the guys comes back and said the condenser is spoiled and you need to replace.

Now whose fault is this ? somebody's negligence to be borne by the customer with his hard earned money.
contactme27 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Heart over mind... ANHC wins the heart... raghu230506 Test-Drives & Initial Ownership Reports 213 13th December 2016 11:43
SX4 OEM HU: By pass surgery for Amp section omishra In-Car Entertainment 75 5th January 2013 11:10
Open open open Sesame!! VJ_MAVRICK Shifting gears 12 10th January 2008 15:24


All times are GMT +5.5. The time now is 06:11.

Copyright ©2000 - 2018, Team-BHP.com
Proudly powered by E2E Networks