This BMW X4 came in for a timing kit replacement after its check engine light came on. The owner also noticed a lag when starting the car. During the job we found oil leaks at the cam magnets and the valve cover. Here is what we fixed, and what it cost.
Job completed: August 2026
| Car | BMW X4 |
|---|---|
| Symptom | Check engine light came on; later a lag when starting the car |
| Fault found | A timing issue needing a timing kit replacement, plus oil leaks at the two cam magnets and the valve cover |
| Repair done | Replaced the timing kit set, the two cam magnets with o-rings and the valve cover set |
| Parts | OEM-grade replacement parts |
| Time taken | Several days |
| Cost | $3,749.60 with GST, each item quoted and approved before it was done |
| Warranty | No warranty term stated for this job |
In late July the owner messaged us that the check engine light had come on, and dropped by for a check. After checking the car, we quoted a timing kit replacement. The car came back for the job in August. On the day it came in, the owner also told us there had been a lag when starting the car for the last two days, and asked us to check that too. The car had been serviced with us before, at 73,000km and again in June at about 82,000km, so we had its history.
The BMW X4 is a performance crossover with an engine that uses a chain-driven timing system to keep the camshafts in sync with the crankshaft. Unlike a timing belt, the chain and its tensioners are designed to last, but not indefinitely. The cam magnets are electrical parts of the variable valve timing system. They are sealed with rubber o-rings, and when a seal fails, oil can seep out around them. The valve cover is the large plastic or alloy cap that seals the top of the engine. When its gasket hardens and shrinks, oil weeps from the seam.
The check engine light visit led to the timing kit quote. When the car came in for the job, the owner also asked us to look at the lag when starting. Our team found it was related to the timing issue we were already fixing.
With the car in for the timing work, our team also found oil leaks at the two cam magnets and at the valve cover. We quoted these to the owner separately, and the owner approved them before we did the work. The four fuel injectors were flagged as a keep-in-view item, not part of this job.
The timing kit was the main job. The oil leaks at the cam magnets and the valve cover were found while the car was already in for it, so fixing them in the same visit saved the owner a separate trip for an oil leak job.
Rubber o-rings and gaskets harden with age and heat, and oil starts to seep past them. It pays to check the seals on the top of the engine whenever that area is worked on.
We replaced the following:
The four fuel injectors were flagged as a keep-in-view item and were not replaced on this visit. Once the work was done, the car was ready to collect. When the owner asked about the start lag, we explained it was related to the timing issue we had just fixed. The owner told us the next day that the car seemed OK so far.
From our team's record of this job. Number plates are pixelated.
On this X4 the final invoice was $3,749.60 with GST. The breakdown: timing kit set $1,950, labour $580, cam magnets with o-rings (two pieces) $290, valve cover set $620. The total before GST was $3,440.
Timing kit jobs vary in cost depending on the engine. The cam magnet and valve cover leaks were found while the car was in for the timing work, so they were fixed in the same visit. Each item was quoted and approved before it was done.
Have the timing system inspected at major service intervals. A start-lag on a cold morning is a useful early signal. Oil weeping from the valve cover or cam magnet area shows up as a film on the engine block or a faint burning smell when the engine is hot. These are worth catching early, before an oil leak causes secondary damage to sensors or belts nearby. Keeping the oil level topped and changed on schedule also reduces wear on the timing chain tensioners.
This BMW X4 (Timing kit replacement, cam magnet and valve cover repair) was handled at 1 Car Service, an independent workshop in Sin Ming AutoCity, Singapore. For BMW, we use dealer-level ISTA diagnostics. We hold a 4.9★ rating from 1,836+ Google reviews.
WhatsApp us your car model and mileage. We will connect ISTA, check the timing system and any related oil leaks, and quote every item clearly before work begins.
On this X4 the timing kit set and labour came to $2,530 before GST. With the cam magnets and valve cover also done in the same visit, the total was $3,749.60 with GST. Cost varies by engine. We quote each item and only do what is approved.
There is no single mileage that fits every car. Get the timing system checked if a warning light comes on, the engine is slow to start, or you hear rattling at start-up. On this X4 the check engine light came on, and after checking the car we quoted a timing kit replacement.
A lag when starting can have several causes, so it needs a proper check. On this X4, the owner noticed the lag in the two days before the car came in for its timing kit. Our team found it was related to the timing issue, and the owner told us the car seemed OK the day after collection.
Yes. We use ISTA, the BMW dealer-level diagnostic system, to read fault codes, check live data and verify repairs. It is the correct tool for clearing timing-related codes and confirming the variable valve timing system is working correctly after a repair.
Yes. We connect ISTA, the BMW dealer-level diagnostic system, use OEM-grade parts, and document the work. You get dealer-level tools and careful work, with clear itemised pricing and personal attention. Every item on this job was quoted and approved before it was done.
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