At Volkswagen Car Service North Shore, we frequently get referrals from other vehicle workshops, who often come to us as a last resort, having failed in their own diagnostic efforts. They bring VW’s to us because they are aware of the reputation we’ve built within the industry, thanks to our mechanics’ specialist knowledge and broad experience working with the Volkswagen marque.

Troubleshooting a Volkswagen Tiguan

VW’s are generally well-built and most models have a reputation for reliability, but occasionally issues arise that take quite a lot of investigation to resolve. For example, a local mechanic recently brought in a popular SUV, the VW Tiguan, which had been suffering an oil leak. After removing and resealing the valve cover to cure the problem, he discovered that the car simply wouldn’t start. Mystified by this and having run some other diagnostic tests, he decided the best course of action was to bring the car to Volkswagen Car Service North Shore for us to resolve.

Our mechanics were tasked with identifying the cause of the no-start problem, rather than the original oil leak, and figure out if the subsequent repair had caused the new issue. That meant finding out exactly what procedures the mechanic had carried out.

Getting Technical with a VW Tiguan FSI Engine Repair

It turned out that the first mechanic had scanned for problems within the engine’s electronic system, which revealed a fault in the cam shaft sensor that led to him replacing it. He also decided to replace the high-pressure fuel pump.

Due to their vast experience with Tiguan engines, our mechanics started to question exactly how the repairs were carried out. For example; were the camshafts ‘locked’ in place before the original mechanic removed them? This particular Tiguan had a CAWA 2.0 FSI engine, and if its camshafts aren’t locked in place before work begins, it can cause serious consequential damage to the engine, by causing the timing-chain to jump. The camshafts and crankshaft are precisely timed in their rotations and if the timing is even slightly out, the pistons will strike the valves and cause engine failure.

Getting the Engine Diagnosis Right

After learning the history of the engine’s repairs, our mechanics hand-cranked the engine and found that it had little or no compression. In fact, a simple test revealed zero compression in No.1 cylinder. The next stage was to remove all four spark plugs and fit a dial gauge in the affected cylinder. We then followed official VW guidelines and removed the top timing cover, to measure the links between the car’s two camshafts and check the timing. This procedure revealed a severe discrepancy, which led us to deduce that the valves had become bent, due to being struck by the pistons.

Removing the Tiguan’s Engine for Inspection

Following these thorough diagnostics, we recommended to the client that the cylinder head be removed for inspection, to reveal the full picture and allow us to provide a quote for repairs. The best way to do that was by removing the engine and placing it on a work-bench for easy access.

Once the cylinder head was removed, we found the inlet ports were suffering from serious carbon deposits. Back when the engine was running, it would doubtless have been noticeably inefficient and performing poorly. But, even worse than this, the exhaust valves were bent out of shape, probably the result of the timing-chain jumping several teeth. It’s rare that a VW engine arrives at Volkswagen Car Service North Shore in such shocking condition.

A Lesson in Never Cutting Corners with Car Engines

Instead of the conventional gaskets, the Tiguan’s CAWA 2.0 FSI engine is sealed using a special, green sealant unique to Volkswagen, which costs $80 for a very small tube. At that price, many less professional mechanics might choose to cut corners and replace the recommended sealant with a generic product, usually with disastrous consequences. You guessed it – in this case the wrong sealant was used on several parts of the engine, including the resealing of the valve cover, the timing cover and the fuel pump assembly. This basically led to premature death of the Tiguan’s engine.

Providing a Competitive Repair Quote for the VW Tiguan

Have no doubt, this is a major and complex repair job, and should only be undertaken by VW Tiguan experts, like Volkswagen Car Service North Shore.

Firstly, we would need to replace those bent valves, then recondition the cylinder head. Next, the engine would have to refitted, the cambelt timing properly checked and its tensioner adjusted accordingly. We would also have to thoroughly rid the engine of that incorrect sealant. Brand new gaskets and other parts would also be required to complete the job. We always aim to offer a competitive quote, whilst doing a thoroughly professional job, and in this case the client was happy with the price and gave the go-ahead.

Investigating the True Cause of the Tiguan’s Engine Problem 

Our team of auto mechanics couldn’t initially figure out why the original removal of the valve cover, even with the cams unlocked, caused so much resultant damage and were determined to get to the bottom of the mystery. Our guys were on a mission!

They got to work reconditioning the cylinder head and removing all the problematic sealant from the timing cover, vacuum pump and fuel pump (a component with absolutely no need for sealant). Once this work was completed, our mechanics soon found that the timing remained out. It’s typically set using a dial gauge instrument and by matching links of different colours to the cam, crank and balance shaft sprockets. Further diagnostics revealed that the bottom pulley had been removed and the crank sprocket damaged, presumably due to its incorrect installation. Neither of these components needed to be removed to address the Tiguan’s original oil leak but this certainly explained why the timing was so far out.

The crank sprocket features a flat spot that matches that on the crank shaft , which is meant to make it impossible to fit incorrectly – but not in this case! Unbelievably, it was actually forced into place by the original mechanic. This led to us having to install a brand new sprocket. We then timed the engine to VW’s official specifications before carefully replacing the engine.

Hey presto! Once all the required lubricants and fluids were replaced, the engine fired up first time and with absolutely no sign of leaks. Unfortunately, this was a costly learning experience for the customer, due to the huge amount of man hours taken up by the diagnostics and repairs. This time and money could all have been saved, if the original mechanic had admitted he was out of his depth and sought expert help to resolve the issue. Volkswagen Car Service North Shore would never make this mistake.

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